Home Laboratory studies of the influence of the working position of the passenger vehicle air suspension on the vibration comfort of children transported in the child restraint system
Article Open Access

Laboratory studies of the influence of the working position of the passenger vehicle air suspension on the vibration comfort of children transported in the child restraint system

  • Damian Frej , Andrzej Zuska and Emilia M. Szumska EMAIL logo
Published/Copyright: March 6, 2021
Download Article (PDF)
Become an author with De Gruyter Brill
Submit Manuscript Author Information
Open Engineering
From the journal Open Engineering Volume 11 Issue 1

Abstract

The article presents the results of laboratory tests on the influence of the choice of the vehicle suspension position and the method of mounting child seats on the vibration comfort of children transported in them. Two child seats were used in the work. The B seat was attached to the vehicle with the ISOfix system, while the A seat was attached in the classic way (with seat belts). During the tests, the values of vertical vibrations were recorded on the seats of child seats, the rear seat of the vehicle and on the basis of ISOfix. The analyzed systems, depending on the method of mounting a child seat, may be characterized by two different vibration transmission chains. They depend on the method of fixing the child seat (the classic way of fixing the seat and the ISOFIX system). The article presents the results of empirical tests carried out at the EUSAMA SA.640 stand, which in these tests acted as a vibration generator with a frequency of 0 to 25 Hz. The analysis of the obtained results confirmed the observations published in previous articles about the negative impact of the use of the ISOfix base on the vibrational comfort of children.

Keywords: child restraint system; comfort; vertical vibration

1 Introduction

In Poland, according to the Road Traffic Act, children under 150 cm tall may only be transported in a vehicle in a safety seat or other restraint [1]. This obligation applies to traveling in vehicles of categories M1, N1, N2 and N3, with the exception of a situation where a child of at least 135 cm cannot travel in a child seat due to its mass and height. According to the European safety certificate ECE R44-04, the child seat must be adapted to both the height and mass of the child. This seat should comply with the requirements set out in the EU regulations or the UNECE regulations concerning child restraint systems in the vehicle [1]. The minimum requirement for the seats to be used is to be approved in accordance with the aforementioned ECE R44 / 04 certificate. Additional requirements for child seats are described in Regulation No. 44 of the United Nations Economic Commission for Europe (UN / ECE) [2]. This document distinguishes five groups of vehicle seats classified according to the child's mass. The classification is presented in Table 1.

Table 1

Classification of vehicle seats according to Regulation 44 ECE / UN [2]

Group Mass Child, kg
0 < 10
0+ < 13
I od 9 do 18
II od 15 do 25
III od 22 do 36

Currently, most passenger vehicles re equipped with the ISOFIX system. The technical requirements for this system are contained in the provisions of Regulations No. 14 and No. 16 of the United Nations Economic Commission for Europe [3, 4]. Each vehicle seat with the ISOFIX system should be attached with the use of specially adapted holders, and also have a Top Tether fastening or a support. Pursuant to Regulation No. 129 of the United Nations Economic Commission for Europe (the so-called i-Size), the use of ISOFIX systems is promoted. The provisions of this standard also require rearward-facing transport of children under 15 months of age, which provides better protection in collisions. The i-Size standard also introduces an additional classification of seats according to the child's height [5].

Many studies and studies devoted to the analysis of accidents involving children show how important it is for safety reasons to transport children in child seats [6,7,8]. Scientists also pay attention to choosing the right vehicle seat and properly fastening the child. The results presented in [9] show that less than half of children aged 0–3 years involved in accidents were properly fastened. Similar conclusions were presented in [10]. Much work and projects were devoted to the development of instructions and applications that help to properly install the vehicle seat in the vehicle. Examples can be found, among others in [11, 12].

Vehicle child seats are constantly being developed and improved. Manufacturers of vehicle seats and scientists are trying to increase the protection of the child while driving and ensure a comfortable journey. The study [13] investigated the relationship between the design features of the seat and the arrangement of the belt and the comfort of driving in a group of children aged 4 to 8 years. The articles analyzed the LATCH seat mounting system [14, 15]. In [16], four methods of fastening seat belts in a rearward facing seat were analyzed. Moreover, the displacement of the seat and physical injuries of the Q1 dummy as suffered during the crash tests are discussed. The article [17] presents the results of analyzes of forces acting in the belts of belts supporting a child in a safety seat. A prototype of a vehicle seat for children weighing more than 20 kg has been presented in [18].

Currently, a lot of research is being conducted to investigate the behavior of a child's body in a forward-facing or rear-facing seat during tests simulating a collision using dummies. The results of these studies can be found, among others in [19,20,21]. The results of the crash tests presented, among others in the works [22,23,24] showed that improper fastening of the child in the seat may cause additional injuries.

The main function of the seat is to ensure the child's safety while traveling and to reduce the effects of possible road incidents. However, the issue of comfort is also important. As the results of the research presented in [25] show, the child's organism shows different resonance frequencies than that of an adult. In the works [26, 27], indicators based on the course of acceleration as a function of time were used to assess the comfort of the child traveling in the seat. Much work and research has been devoted to examining the frequencies of vertical vibrations transmitted from the rear seat vehicle and seat to the child's body. Examples can be found, among others in the works [28,29,30]. The suspension of the vehicle is an important aspect in considering the issue of passenger comfort. Vibrations originating from the places of contact of the wheels with the surface are transferred to the body and are felt by the vehicle users. This is confirmed by the research results presented in the works [30,31,32]. Increasingly, vehicle owners decide to purchase vehicles with active, semi-active, hydropneumatic or pneumatic suspension, which significantly improve the vibration comfort of driving. The paper [33] shows a comparison of active and passive suspension. Based on the test results, it was found that the determined values of the RMS index of accelerations recorded on the seat of a vehicle equipped with active suspension were lower than in the case of a vehicle with passive suspension. The article [34] analyzes the accelerations and longitudinal displacements of selected parts of the human body. The authors concluded that better driving comfort can be obtained by using a semi-active suspension.

Currently, in terms of comfort, an important issue is the impact of vibrations on the child's body depending on the type of seat used and the child's mass. In this study, an analysis of the influence of vertical vibrations transmitted from the body on the body of a child seated in various types of vehicle seats was undertaken. Tests were carried out with different settings of the vehicle air suspension.

2 Measurement methodology

The experimental studies were conducted under laboratory conditions. During the tests, the wheels of the rear axle of an Audi A6 passenger vehicle equipped with air suspension were vibrated by means of measuring plates of the EUSAMA SA device. 640. The EUSAMA SA640 device is used to test shock absorbers using the EUSAMA method and is part of the Bosch Beissbarth diagnostic line. The Eusam method is based on the kinematic excitation of the road wheel to vertical vibrations with a constant amplitude in the range of 4 to 8 mm and a frequency varying from the initial value of about 25 Hz to zero. In the experimental research, the EUSAMA SA640 device acted as a vibration generator.

The main objective of the experiment was to measure and analyze the propagation of vertical vibrations in two subsystems: vehicle body – vehicle seat – child seat, which differed in the method of mounting a child seat, taking into account three different positions of the passenger vehicle suspension. The first method of fixing the seat was to use the ISOfix base, which allows for quick and stable mounting of the child seat in the vehicle without the use of standard seat belts. However, the second method of fastening a child seat in a passenger vehicle requires the use of standard seat belts. Two seats were used in the experiment (Figure 1):

  • Seat A – Avionaut Pixel – designed for transporting children weighing up to 13 kg and height 45–86 cm. The vehicle seat's own mass is 2.5 kg. The seat is mounted directly to the rear seat of the vehicle using standard seat belts

  • Seat B – Avionaut AeroFIX – is designed to transport children with a height of 67–105 cm and a mass of up to 17.5 kg. The vehicle seat's own mass is 4 kg. The seat is mounted on the rear seat of a passenger vehicle in the direction of travel using the Avionaut IQ ISOfix base. The base was connected to the vehicle's ISOFIX system.

Figure 1 Tested child seats: a) seat for transporting children up to 17.5 kg – “A”, b) seat for transporting children up to 13 kg – “B”
Figure 1

Tested child seats: a) seat for transporting children up to 17.5 kg – “A”, b) seat for transporting children up to 13 kg – “B”

During the experimental tests, the Avionaut AeroFIX “B” seat was placed on the left side of the rear seat, which was attached to the ISOfix base (Figure 2), while the Avionaut Pixel seat was placed on the right side of the rear seat of the passenger vehicle, which was attached in a classic way, i.e. behind with the 3-point seat belts.

Figure 2 IQ ISOfix base for attaching child seats
Figure 2

IQ ISOfix base for attaching child seats

During the experiment, the vehicle seats were loaded with a mass imitating the mass of a child. The tests were carried out for the masses: 5, 7.5, 10, 12.5 and 15 kg. During the tests, the vehicle was equipped with 255/35 ZR19 tires. The tires were balanced before the tests. The experimental tests were carried out for the nominal pressure in the tires and for the value of pressure reduced and increased by 15 % taking into account three suspension configurations (Figure 3).

Figure 3 View of the air suspension height control panel in an Audi A6 passenger vehicle
Figure 3

View of the air suspension height control panel in an Audi A6 passenger vehicle

The research vehicle was a passenger vehicle with an air suspension system. In this vehicle, the user can adjust the suspension setting to the road conditions. This allows to reduce vibrations generated by uneven road surface, and thus improve driving comfort. The vehicle was equipped with an air suspension that can take one of three positions: dynamic, comfortable and upper. The air suspension uses air bags supplied with air by the compressor. The work of the suspension system is coordinated by an electronic module that works with the pressure distributor and valves to regulate the height of the body. During the research, acceleration was recorded using three-way acceleration sensors. Sensors using semi-flexible measuring discs are placed on: on the rear seat of the vehicle, on the seat and backrest of the child seat and in the case of the A seat based on IQ ISOfix. The research used the LMS SCADAS Recorder SCR02 digital recorder, which enables automatic operation after setting the measurement parameters. Data was recorded directly to the measuring computer.

The rms, VDV and SEAT indicators were used to analyze the truncated vibrations recorded on the seat of the child seats, the ISOfix base and the rear seat under the A seat.

The main assessment of the influence of vibrations on the vibration comfort while driving is the rms value of accelerations acting in the vertical direction (1). For accelerations a (t) registered as the occurring stationary realization of the rms stochastic process, it is most often an indicator of the vibration comfort assessment.

(1) r.m.s=[1T∫0Ta2(t)dt]12

where:

  • a(t) – vertical acceleration value m/s2 recorded as a function of time t

  • T – segment of the measurement duration, p.

The VDV (Vibration Dose Value) indicator was developed for vibration analysis of the whole human body. The rms and VDS values are not correlated with each other, because they accentuate the measured acceleration amplitudes in different ways. Both indicators do not estimate the impact of momentary shocks.

(2) VDV=[∫0Ta4(t)dt]14

where:

  • a(t) – the frequency weighted acceleration as a function of in time, m/s2

  • T – is the duration of measurement in (s).

Using the accelerations recorded in selected points of the tested subsystem, the SEAT index was determined. This index allows to assess the degree of damping of vibrations transmitted to the seat [5, 18]. This demonstrates the ability of the seat to damp vibrations in the vehicle in such a way as to protect the driver and passengers from excessive vibration. The SEAT value (3) is used to describe the vibration isolation of the vehicle seat [27].

(3) SEAT=V.D.VFV.D.VP

where:

  • V.D.VF – Vibration Dose Value determined for the vehicle seat

  • V.D.VP – Vibration Dose Value determined for the surface to which the vehicle seat is attached

3 Data analysis

The results of the measurements were used to determine the time courses of truncated accelerations. Examples of vertical vibrations recorded on the seat of the tested seats are presented in Figures 4 to 11. When comparing the courses of vertical vibration acceleration for the two tested seats, it should be noted that higher acceleration values were recorded on the seat of the vehicle seat. red B. In addition, the vertical accelerations recorded from the ISOfix database were greater than the vertical accelerations recorded on the rear seat of the test vehicle. The greatest difference in the acceleration of vertical vibrations recorded on the seat of child seats occurs when the seats are loaded with a mass of 5 kg and when the Audi A6 suspension is in the raised position. The smallest difference in the acceleration of vertical vibrations recorded on the seats of child seats occurs when the suspension is set in a dynamic position and the seat is loaded with a mass of 15 kg.

Figure 4 Vertical accelerations recorded on the seat B and ISOfix base (suspension in a dynamic position, the seat is loaded with a mass of 5 kg)
Figure 4

Vertical accelerations recorded on the seat B and ISOfix base (suspension in a dynamic position, the seat is loaded with a mass of 5 kg)

Figure 5 Vertical accelerations recorded on the seat B and ISOfix base (suspension in a raised position, the seat is loaded with a mass of 5 kg)
Figure 5

Vertical accelerations recorded on the seat B and ISOfix base (suspension in a raised position, the seat is loaded with a mass of 5 kg)

Figure 6 Vertical accelerations recorded on the seat B and ISOfix base (suspension in a dynamic position, the seat is loaded with a mass of 15 kg)
Figure 6

Vertical accelerations recorded on the seat B and ISOfix base (suspension in a dynamic position, the seat is loaded with a mass of 15 kg)

Figure 7 Vertical accelerations recorded on the seat B and ISOfix base (suspension in a raised position, the seat is loaded with a mass of 15 kg)
Figure 7

Vertical accelerations recorded on the seat B and ISOfix base (suspension in a raised position, the seat is loaded with a mass of 15 kg)

Figure 8 Vertical accelerations recorded on the seat A and ISOfix base (suspension in a dynamic position, the seat is loaded with a mass of 5 kg
Figure 8

Vertical accelerations recorded on the seat A and ISOfix base (suspension in a dynamic position, the seat is loaded with a mass of 5 kg

Figure 9 Vertical accelerations recorded on the seat A and ISOfix base (suspension in a raised position, the seat is loaded with a mass of 5 kg)
Figure 9

Vertical accelerations recorded on the seat A and ISOfix base (suspension in a raised position, the seat is loaded with a mass of 5 kg)

Figure 10 Vertical accelerations recorded on the seat A and ISOfix base (suspension in a dynamic position, the seat is loaded with a mass of 15 kg)
Figure 10

Vertical accelerations recorded on the seat A and ISOfix base (suspension in a dynamic position, the seat is loaded with a mass of 15 kg)

Figure 11 Vertical accelerations recorded on the seat A and ISOfix base (suspension in a raised position, the seat is loaded with a mass of 15 kg)
Figure 11

Vertical accelerations recorded on the seat A and ISOfix base (suspension in a raised position, the seat is loaded with a mass of 15 kg)

Above, you should compile next to each other graphs of the time courses of vertical accelerations for different (preferably extremely different) suspension work positions but for identical loads. This time, the differences in the acceleration values resulting from the position in which the suspension works should be emphasized in the paper.

The rms, VDV and SEAT indicators were used to analyze the propagation of vibrations on the seats of child seats, the rear seat and the ISOfix base. The values of the rms index of accelerations recorded on the seats of the tested child seats are summarized in Table 2. The highest values are marked in red, and the lowest in green. The highest rms values of 2.61 m/s2 for seat A and 3.053 m/s2 for seat B were recorded when the vehicle was suspended in the raised position and the seats were loaded with a mass of 5 kg. These values prove that for children weighing 5 kg, setting the suspension in the raised position is unfavorable.

Table 2

Summary of RMS values for the tested child safety seats

Suspension position Mass child, kg Tire pressure Child seat A Child seat B
Location of the acceleration sensor
Seat of Child seat Seat of Child seat
Dynamic 5 85% of nominal pressure 1.278 2.388
Nominal pressure 1.307 2.490
115% of nominal pressure 2.524 2.872
7,5 85% of nominal pressure 1.225 2.122
Nominal pressure 1.319 2.201
115% of nominal pressure 1.584 2.260
10 85% of nominal pressure 1.572 1.891
Nominal pressure 1.606 1.935
115% of nominal pressure 1.620 1.934
12,5 85% of nominal pressure 1.107 1.324
Nominal pressure 1.117 1.358
115% of nominal pressure 1.076 1.296
15 85% of nominal pressure 1.066 1.306
Nominal pressure 1.089 1.341
115% of nominal pressure 1.016 1.236
Raised 5 85% of nominal pressure 1.149 1.971
Nominal pressure 2.610 3.053
115% of nominal pressure 2.578 2.848
7,5 85% of nominal pressure 1.292 2.112
Nominal pressure 1.356 2.118
115% of nominal pressure 2.051 2.459
10 85% of nominal pressure 1.308 1.696
Nominal pressure 1.521 1.924
115% of nominal pressure 1.619 2.014
12,5 85% of nominal pressure 0.928 1.000
Nominal pressure 0.972 1.125
115% of nominal pressure 0.988 1.123
15 85% of nominal pressure 0.793 0.921
Nominal pressure 1.034 1.182
115% of nominal pressure 1.074 1.214
Comfortable 5 85% of nominal pressure 2.481 1.122
Nominal pressure 2.509 1.262
115% of nominal pressure 1.895 1.297
7,5 85% of nominal pressure 1.378 1.221
Nominal pressure 1.399 1.258
115% of nominal pressure 1.372 1.184
10 85% of nominal pressure 1.647 0.978
Nominal pressure 1.852 1.051
115% of nominal pressure 1.897 1.084
12,5 85% of nominal pressure 1.122 0.997
Nominal pressure 1.262 1.144
115% of nominal pressure 1.297 1.184
15 85% of nominal pressure 1.221 1.015
Nominal pressure 1.258 1.027
115% of nominal pressure 1.184 0.998

Table 3 presents the results of the VDV and SEAT indicators. The highest value of the VDV index was 6.071 m/s1.75 for the A car seat with a mass of 7.5 kg. On the other hand, the highest value of the SEAT indicator is 3.727, also for the seat A with a load of 7.5 kg.

Table 3

Results of the VDV and SEAT indicators

Suspension position Mass child, kg Tire pressure Child seat A Child seat B
Location of the acceleration sensor
Seat of Child seat Seat of Child seat
VDV SEAT VDV SEAT
Dynamic 5 85% of nominal pressure 3.812 2.259 1.883 0.843
Nominal pressure 3.873 2.246 2.196 1.004
115% of nominal pressure 3.326 2.190 2.264 0.483
7,5 85% of nominal pressure 2.405 1.388 3.977 1.012
Nominal pressure 2.490 1.425 4.229 1.030
115% of nominal pressure 6.071 3.727 4.505 1.265
10 85% of nominal pressure 2.166 1.214 3.413 0.914
Nominal pressure 4.749 3.608 4.629 1.538
115% of nominal pressure 5.457 3.621 4.473 1.368
12,5 85% of nominal pressure 2.532 1.608 2.101 1.027
Nominal pressure 2.594 1.629 2.173 0.947
115% of nominal pressure 2.507 1.662 2.062 0.725
15 85% of nominal pressure 1.966 1.210 3.265 1.241
Nominal pressure 2.206 1.314 3.394 1.242
115% of nominal pressure 2.930 1.761 3.505 1.270
Raised 5 85% of nominal pressure 2.253 1.731 3.561 1.717
Nominal pressure 2.386 1.667 3.456 1.459
115% of nominal pressure 3.737 2.680 3.865 1.612
7,5 85% of nominal pressure 2.626 1.111 3.525 2.071
Nominal pressure 3.124 1.087 3.809 2.020
115% of nominal pressure 3.162 1.073 3.877 1.872
10 85% of nominal pressure 2.877 0.735 3.098 1.556
Nominal pressure 2.978 0.760 3.165 1.584
115% of nominal pressure 2.997 0.761 3.134 1.600
12,5 85% of nominal pressure 2.408 0.727 2.729 1.528
Nominal pressure 2.598 0.782 3.064 1.498
115% of nominal pressure 2.937 0.766 3.239 1.628
15 85% of nominal pressure 1.883 1.082 3.176 1.395
Nominal pressure 2.196 1.119 3.666 1.558
115% of nominal pressure 2.264 1.117 3.789 1.452
Comfortable 5 85% of nominal pressure 1.984 0.548 2.240 0.988
Nominal pressure 1.986 0.548 2.259 0.917
115% of nominal pressure 1.981 0.547 2.228 0.684
7,5 85% of nominal pressure 1.790 0.534 1.819 0.743
Nominal pressure 1.982 0.428 2.060 0.330
115% of nominal pressure 1.930 0.506 2.013 0.599
10 85% of nominal pressure 2.101 1.166 3.342 1.599
Nominal pressure 2.173 1.166 3.389 1.254
115% of nominal pressure 2.062 1.131 3.157 0.993
12,5 85% of nominal pressure 1.920 0.564 2.300 1.198
Nominal pressure 1.943 0.557 2.363 0.897
115% of nominal pressure 1.817 0.526 2.115 0.682
15 85% of nominal pressure 1.543 0.528 1.683 0.750
Nominal pressure 2.042 0.578 2.255 0.680
115% of nominal pressure 2.093 0.575 2.302 0.551

The maximum values of the indexes were recorded during the dynamic suspension adjustment of the passenger car. On the other hand, the smallest value when adjusting the suspension comfortably. It should be noted that the lowest value of the VDV index is 1.543 m/s1.75 for the seat A, and was recorded for a mass of 15 kg. On the other hand, the lowest value of the SEAT indicator is 0.330 for seat B with a mass of 7.5 kg

Assuming that the pressure in the tires will be maintained at the nominal level, for children weighing 5 kg in the A vehicle seat, the most advantageous in terms of vibration comfort turned out to be the dynamic position of the suspension, while for children transported in the B seat, the most advantageous position was to set the suspension to the comfort position. The most unfavorable suspension setting from the point of view of vibration comfort for children weighing 5 kg turns out to be the best for children weighing 15 kg, provided that the pressure in the tires is reduced by 15%. With the nominal air pressure in the tires, the most advantageous for children weighing 15 kg in the B seat (fixed in the classic way) is to set the suspension to the comfort position, while for children of the same mass but transported in the A seat (fastened with the ISOfix system), the best is to shift the suspension into dynamic position.

The ISO 2631-1 standard, in addition to the effective rms values, also provides for the use of the VDV index to assess the impact of vertical vibrations on a person in a sitting position [35]. The values of this index for all (forty) measurement tests are presented in Figures 12–16. They illustrate the influence of the suspension position and air pressure in the tires of the test vehicle on the values of the VDV index of accelerations recorded on the seats of the tested child seats. The influence of the operating position of the suspension and air pressure in the tires on the VDV index values was analyzed for four different load variants of the tested seats.

Figure 12 VDV index for the tested seats, loaded with a mass of 5 kg during the tests
Figure 12

VDV index for the tested seats, loaded with a mass of 5 kg during the tests

Figure 13 VDV index for the tested seats, loaded with a mass of 7.5 kg during the tests
Figure 13

VDV index for the tested seats, loaded with a mass of 7.5 kg during the tests

Figure 14 VDV index for the tested seats, loaded with a mass of 10 kg during the tests
Figure 14

VDV index for the tested seats, loaded with a mass of 10 kg during the tests

Figure 15 VDV index for the tested seats, which were loaded with a mass of 12.5 kg during the tests
Figure 15

VDV index for the tested seats, which were loaded with a mass of 12.5 kg during the tests

Figure 16 VDV index for vehicle seats that were loaded with a mass of 15 kg during the tests
Figure 16

VDV index for vehicle seats that were loaded with a mass of 15 kg during the tests

The analyzes of the VDV index show that when the B (red) seat was loaded with a mass less than or equal to 7.5 kg, it is more advantageous in terms of vibration comfort to set the vehicles suspension to the comfort position. For other load variants, it is more advantageous to set the suspension in a raised or dynamic position in terms of vibration comfort. The situation is completely different when we analyze the values of the VDV index for the A (gray) seat. This time, in four out of five cases where the seat is loaded (5 kg, 7.5 kg, 10 kg, 15 kg) at nominal air pressure in the tires, it is more advantageous in terms of vibration comfort to set the suspension in a dynamic or raised position. In the case where the A (gray) seat is loaded with a mass of 5 kg, the best comfort in terms of comfort is setting the suspension in the raised position, assuming that the air pressure in the wheels will be reduced by 15% compared to the nominal pressure. In most cases, as the pressure in the vehicle wheels increases, the VDV values also increase.

Figures 17–20 show the values of the SEAT indicator for seats with a mass of 7.5 kg, 10 kg, 12.5 kg and 15 kg. The analysis shows that in the vast majority of cases, the values of this index determined for the B (red) seat were higher than the values determined for the A (gray) seat. This shows that the vibrations transferred from the ISOfix base to the red seat were reduced to a greater extent than the vibrations transmitted from the rear seat cushion to the A (gray) seat, which was attached in a conventional manner. The opposite was observed in only ten out of thirty-six cases. It should be emphasized that most of these cases (nine) were reported when the vehicle seats were loaded with a mass of 7.5 kg.

Figure 17 SEAT indicator on the seat of the tested child seats with a load of 7.5 kg
Figure 17

SEAT indicator on the seat of the tested child seats with a load of 7.5 kg

Figure 18 SEAT indicator on the seat of the tested child seats with a load of 10 kg
Figure 18

SEAT indicator on the seat of the tested child seats with a load of 10 kg

Figure 19 SEAT indicator on the seat of the tested child seats with a mass of 12.5 kg
Figure 19

SEAT indicator on the seat of the tested child seats with a mass of 12.5 kg

Figure 20 SEAT indicator on the seat of the tested child seats with a mass of 15 kg
Figure 20

SEAT indicator on the seat of the tested child seats with a mass of 15 kg

4 Conclusions

The subject of the research is part of the issue of the vibration comfort of children transported in child seats. The presented research is a part of a whole series of research carried out by employees of the Department of Motor Vehicles and Transport of the Kielce University of Technology. They concern the spread of vertical bastards in the following system: vehicle (vehicle floor) – vehicle seat cushion – child seat. In the conducted research, it was noticed that the position of the suspension of a vehicle equipped with air suspension may have a significant impact on the transmission of vibrations from the road surface to the seat of the child seat.

The review of literature items allowed to state that child seats are the subject of many studies and analyzes in terms of the passive safety of children transported in them, while static (comfort) and vibration comfort seem to be completely overlooked. This can be proved by a very modest number of publications describing these issues. The authors of these publications (regarding the comfort of children transported in child seats) focus mainly on the place, position and method of fastening the seats.

The authors of this study decided to draw attention to two elements, overlooked by the authors of other publications, which significantly affect the assessment of the vibration comfort of children transported in child seats. These elements include: the mass of the child and the characteristics of the car suspension in which the child seats are attached.

Laboratory tests of child seats, in terms of vibration comfort, are quite troublesome to carry out because the applicable regulations exclude the possibility of children participating in them. Therefore, the authors plan to carry out a series of operational tests involving children of various mass and anthropometric dimensions, as permitted by the regulations. The research results obtained in this way will be used to develop a concept and build an innovative vibration reduction system that will be integrated into the child seat mounting system. In addition, it is planned to develop the currently missing criteria for assessing the vibration comfort of children transported in child seats.

The paper presents the results of empirical tests carried out at the EUSAMA SA.640 stand, which in these tests acted as a generator of vibrations with a frequency of 0 to 25 Hz. It should be noted that the air suspension from the assembly is to improve the traction parameters of the vehicle. Such solutions are to ensure optimal reduction of vibrations coming from the road surface. Consequently, the air suspension is to improve driving comfort. The ISOfix base separates the seat from the rear seat of the vehicle. This system enables quick and stable mounting of a child seat in the vehicle. In addition, together with the seat, the ISOfix base creates a system that is subject to acceleration from the vehicles floor plate. Consequently, it contributes to the deterioration of the vibration comfort of children carried in the seat. The negative impact of separating the child seat from the rear seat of a passenger vehicle with the ISOfix base is confirmed by the r.m.s and VDV values determined for the B seat, which were higher than the rms values and VDV values determined for the A seat fitted in a classic way.

They found that in most of the tests conducted for the A seat, the comfort position was less favorable in terms of vibration comfort than the dynamic suspension position. In turn, for children weighing from 7.5 kg to 15 kg transported in a red seat, it is more advantageous in terms of vibration comfort to set the suspension in the comfort position. Noteworthy is the fact that it has a significant impact on the vibration comfort, the mass of the child carried in the seat and the pressure in the tires of the vehicle.

References

[1] Polish Road Traffic Act of 20 June 1997 (Ustawa z dnia 2 czerwca 1997 r. Prawo o ruchu drogowym, Dz. U. 1997 Nr 98 poz. 602), avalaible on https://isap.sejm.gov.pl/isap.nsf/download.xsp/WDU19970980602/U/D19970602Lj.pdfSearch in Google Scholar

[2] Regulation No 44 of the Economic Commission for Europe of the United Nations (UN/ECE) – Uniform provisions concerning the approval of restraining devices for child occupants of power-driven vehicles (‘Child Restraint Systems’).Search in Google Scholar

[3] Regulation No 16 of the Economic Commission for Europe of the United Nations (UN/ECE) – Uniform provisions concerning the approval of: I. safety-belts, restraint systems, child restraint systems and Isofix child restraint systems for occupants of power-driven vehicles II. vehicles equipped with safety-belts, restraint systems, child restraint systems and Isofix child restraint systems,Search in Google Scholar

[4] Regulation No 129 of the Economic Commission for Europe of the United Nations (UN/ECE) – Uniform provisions concerning the approval of enhanced Child Restraint Systems used on board of motor vehicles (ECRS)Search in Google Scholar

[5] K. Omari, O. Baron-Epel, Low rates of child restraint system use in cars may be due to fatalistic beliefs and other factors, Transportation Research Part F: Traffic Psychology and Behaviour, Volume 16, January 2013, pp. 53–59,10.1016/j.trf.2012.08.010Search in Google Scholar

[6] S.L. Bachman, G.A. Salzman, R.V. Burke, H. Arbogast, P. Ruiz, J. S. Upperman, Observed child restraint misuse in a large, urban community: Results from three years of inspection events, Journal of Safety Research Volume 56, February 2016, pp. 17–22.10.1016/j.jsr.2015.11.005Search in Google Scholar PubMed

[7] P.A. Skjerven-Martinsen, T.B. Naess, T. Hansen, A. Staff, Stray-Pedersen, Observational study of child restraining practice on Norwegian high-speed roads: Restraint misuse poses a major threat to child passenger safety, Accident Analysis & Prevention, Volume 59, October 2013, pp. 479–486.10.1016/j.aap.2013.07.023Search in Google Scholar PubMed

[8] G. Lee, C.N. Pope, A. Nwosu, L.B. McKenzie, M. Zhu, Child passenger fatality: Child restraint system usage and contributing factors among the youngest passengers from 2011 to 2015, Journal of Safety Research, Volume 70, September 2019, pp. 33–38,10.1016/j.jsr.2019.04.001Search in Google Scholar PubMed PubMed Central

[9] M. Roynard, P. Silverans, Y. Casteels, P. Lesire, National roadside survey of child restraint system use in Belgium, Accident Analysis & Prevention, Volume 62, January 2014, pp. 369–376.10.1016/j.aap.2013.08.021Search in Google Scholar PubMed

[10] D.C. Schwebel, M. A. Tillman, M. Crew, M. Muller, A. Johnston, Using interactive virtual presence to support accurate installation of child restraints: Efficacy and parental perceptions, Journal of Safety Research, Volume 62, September 2017, pp. 235–243.10.1016/j.jsr.2017.06.018Search in Google Scholar PubMed

[11] K.D. Klinich, M.A. Manary, C.A. C. Flannagan, S.M. Ebert, L.A. Malik, P.A. Green, M. P. Reed, Effects of child restraint system features on installation errors, Applied Ergonomics, Volume 45, Issue 2, Part B, March 2014, pp. 270–277.10.1016/j.apergo.2013.04.005Search in Google Scholar PubMed

[12] B. Albanese, K. Bohman, L. Bilston, S. Koppel, J. L. Charlton, J. Olivier, L. Keay, J. Brown, Influence of child restraint system design features on comfort, belt fit and posture, Safety Science, Volume 128, August 2020, 104707.10.1016/j.ssci.2020.104707Search in Google Scholar

[13] J. B. Cicchino, J. S. Jermakian, Vehicle characteristics associated with LATCH use and correct use in real-world child restraint installations, Journal of Safety Research, Volume 53, June 2015, pp. 77–85, https://www.sciencedirect.com/science/article/pii/S002243751500021310.1016/j.jsr.2015.03.009Search in Google Scholar PubMed

[14] J. S. Jermakian, K. D. Klinich, N. R. Orton, C. A. C. Flannagan, M. A. Manary, L. A. Malik, Prabha Narayanaswamy, Factors affecting tether use and correct use in child restraint installations, Journal of Safety Research, Volume 51, December 2014, pp. 99–108.10.1016/j.jsr.2014.09.011Search in Google Scholar PubMed

[15] L. Peng, Y. Han, D. Pan, K. Mizuno, Constrained Path Optimization in G0 + Group Children Restraint System Based on UN R129, Proceedings of 9th International Conference on Measuring Technology and Mechatronics Automation (ICMTMA), 14–15 January 2017, Changsha, China.10.1109/ICMTMA.2017.0050Search in Google Scholar

[16] A. Muszyński, P. Trzaska, J. Wicher, Ł. Mazurkiewicz, Analysis of the forces developing in the straps of the belts that restrain a child in a safety seat, The Archives of Automotive Engineering – Archiwum Motoryzacji; 67(1), 2015, pp. 113–126.Search in Google Scholar

[17] C. Taff, M. Franco, R. Chung, S. PremDas, Adjustable booster child restraint system to enhance safety, Proceedings of IEEE 37th Annual Northeast Bioengineering Conference (NEBEC), pp. 1–3.Search in Google Scholar

[18] E. Rola, D. Wdowicz, Is it safer to transport a three-year-old child in a forward-facing child restraint system or in a rear-facing one while head-on collision?, Proceedings of International Interdisciplinary PhD Workshop (IIPhDW), 9–12 May 2018, Swinoujście, Poland.10.1109/IIPHDW.2018.8388340Search in Google Scholar

[19] Y. Han, L. Yuan Peng, D. Pan, H. Cong Tang, H. Huang, K. Mizuno, Soft Tissue Injury Risk in Chest and Abdomen of 3YO child Based on CRS Dynamic Load, Proceedings of 10th International Conference on Measuring Technology and Mechatronics Automation (ICMTMA), 10–11 February 2018, Changsha, China.10.1109/ICMTMA.2018.00139Search in Google Scholar

[20] W. Kai, B. Peng, M. Weijie, Research on the Influence to Rear Child Dummy Injure of Safe Seat in Frontal Crash Test, Proceedings of Fifth International Conference on Measuring Technology and Mechatronics Automation, 16–17 January 2013, Hong Kong, China.Search in Google Scholar

[21] P. Posuniak, M. Jaśkiewicz, K. Kowalski, F. Dąbrowski, Child restraint systems: Problems related to the safety of children transported in booster seats (without integral safety belts), Proceedings of XI International Science-Technical Conference Automotive Safety, 18–20 April 2018, Casta, Slovakia.10.1109/AUTOSAFE.2018.8373352Search in Google Scholar

[22] Y. Han, J. Xie, K. Mizuno, H. Huang, G. Renhong, C. Anguo, Research on the Risk of Child Occupant Injury Based on Offset Impact, Proceedings of Eighth International Conference on Measuring Technology and Mechatronics Automation (ICMTMA), 11–12 March 2016, Macau, China.10.1109/ICMTMA.2016.138Search in Google Scholar

[23] H. Yong, L. Xiaoping, K. Miuzno, G. Renhong, C. Anguo, Parameter Optimization of Child Restraint System Based on Orthogonal Experiment, Proceedings of Eighth International Conference on Measuring Technology and Mechatronics Automation (ICMTMA), 11–12 March 2016, Macau, China.10.1109/ICMTMA.2016.114Search in Google Scholar

[24] J. Giacomin, S Gallo, In-vehicle vibration study of child safety seats, Ergonomics, 15; 46(15), 2003, pp. 1500–1512.10.1080/0014013032000121642Search in Google Scholar PubMed

[25] J. Wicher, D. Więckowski, Influence of vibrations of the child seat on the comfort of child's ride in a car, Maintenance And Reliability, 4, 2010, pp. 102–110.Search in Google Scholar

[26] D.P. Frej, A. Zuska, K. Cadge, Analysis of vertical vibrations affecting a child transported in a child seat during a car passing over the release speed bump, The Archives of Automotive Engineering – Archiwum Motoryzacji, 86(4), 2019, pp.111–125.10.14669/AM.VOL86.ART8Search in Google Scholar

[27] S. Jin Park, S. Nam Min, M. Subramaniyam, Heeran Lee, Dong Gyun Kim, Cheol Pyo Hong, Vibration Effect Investigation in Baby Car Seats and Automobile Seats, SAE Technical Paper 2014-01-0462, 2014.10.4271/2014-01-0462Search in Google Scholar

[28] T. Gromadowski, D. Więckowski, Analysis of vertical vibrations acting on children in child car seats, Journal of KONES Powertrain and Transport, Vol. 20, No. 1, 2013, pp. 359–366.10.3846/transbaltica2013.012Search in Google Scholar

[29] J. Giacomin, S. Gallo, In-vehicle vibration study of child safety seats, Ergonomics, 15; 46(15), 2003, pp. 1500–1512.10.1080/0014013032000121642Search in Google Scholar

[30] A. Sezgin, Yunus Z. Arslan, Analysis of the vertical vibration effects on ride comfort of vehicle driver, Journal of Vibroengineering, Vol. 14, Issue 2, 2012, pp. 559–571.Search in Google Scholar

[31] M. Nagai, H. Yoshida, T. Tohtake, Y. Suzuki, Coupled vibration of passenger and lightweight car-body in consideration of human-body biomechanics, Vehicle System Dynamics, International Journal of Vehicle Mechanics and Mobility, Volume 44, 2006, pp. 601–611.10.1080/00423110600879361Search in Google Scholar

[32] R. Burdzik, Identification of structure and directional distribution of vibration transferred to car-body from road roughness, Journal of Vibroengineering, Vol. 16, Issue 1, 2014, pp. 324–333.Search in Google Scholar

[33] A. Shirahatt, P.S. Prasad, P. Panzade, M.M. Kulkarni, Optimal Design of Passenger Car Suspension for Ride and Road, Journal of the Brazilian Society of Mechanical Sciences and Engineering, vol. 30 no.1, 2008.10.1590/S1678-58782008000100010Search in Google Scholar

[34] D.V.A. Rama Sastry, K.V. Ramanaa, N. Mohan Rao, M. Phani Kumar, V.S.S. Rama Chandra Reddy, Evaluation of human exposure to vibrations using quarter car model with semi-active suspension, International Journal of Vehicle Structures and Systems, Vol. 10, Issue 4, 2018, pp. 268–272.10.4273/ijvss.10.4.08Search in Google Scholar

[35] ISO 2631-1:1997 Mechanical vibration and shock – Evaluation of human exposure to whole-body vibration – Part 1: General requirements.Search in Google Scholar
Received: 2020-09-16
Accepted: 2021-01-03
Published Online: 2021-03-06

© 2021 Damian Frej et al., published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 International License.

Articles in the same Issue

  1. Regular Articles
  2. Electrochemical studies of the synergistic combination effect of thymus mastichina and illicium verum essential oil extracts on the corrosion inhibition of low carbon steel in dilute acid solution
  3. Adoption of Business Intelligence to Support Cost Accounting Based Financial Systems — Case Study of XYZ Company
  4. Techno-Economic Feasibility Analysis of a Hybrid Renewable Energy Supply Options for University Buildings in Saudi Arabia
  5. Optimized design of a semimetal gasket operating in flange-bolted joints
  6. Behavior of non-reinforced and reinforced green mortar with fibers
  7. Field measurement of contact forces on rollers for a large diameter pipe conveyor
  8. Development of Smartphone-Controlled Hand and Arm Exoskeleton for Persons with Disability
  9. Investigation of saturation flow rate using video camera at signalized intersections in Jordan
  10. The features of Ni2MnIn polycrystalline Heusler alloy thin films formation by pulsed laser deposition
  11. Selection of a workpiece clamping system for computer-aided subtractive manufacturing of geometrically complex medical models
  12. Development of Solar-Powered Water Pump with 3D Printed Impeller
  13. Identifying Innovative Reliable Criteria Governing the Selection of Infrastructures Construction Project Delivery Systems
  14. Kinetics of Carbothermal Reduction Process of Different Size Phosphate Rocks
  15. Plastic forming processes of transverse non-homogeneous composite metallic sheets
  16. Accelerated aging of WPCs Based on Polypropylene and Birch plywood Sanding Dust
  17. Effect of water flow and depth on fatigue crack growth rate of underwater wet welded low carbon steel SS400
  18. Non-invasive attempts to extinguish flames with the use of high-power acoustic extinguisher
  19. Filament wound composite fatigue mechanisms investigated with full field DIC strain monitoring
  20. Structural Timber In Compartment Fires – The Timber Charring and Heat Storage Model
  21. Technical and economic aspects of starting a selected power unit at low ambient temperatures
  22. Car braking effectiveness after adaptation for drivers with motor dysfunctions
  23. Adaptation to driver-assistance systems depending on experience
  24. A SIMULINK implementation of a vector shift relay with distributed synchronous generator for engineering classes
  25. Evaluation of measurement uncertainty in a static tensile test
  26. Errors in documenting the subsoil and their impact on the investment implementation: Case study
  27. Comparison between two calculation methods for designing a stand-alone PV system according to Mosul city basemap
  28. Reduction of transport-related air pollution. A case study based on the impact of the COVID-19 pandemic on the level of NOx emissions in the city of Krakow
  29. Driver intervention performance assessment as a key aspect of L3–L4 automated vehicles deployment
  30. A new method for solving quadratic fractional programming problem in neutrosophic environment
  31. Effect of fish scales on fabrication of polyester composite material reinforcements
  32. Impact of the operation of LNG trucks on the environment
  33. The effectiveness of the AEB system in the context of the safety of vulnerable road users
  34. Errors in controlling cars cause tragic accidents involving motorcyclists
  35. Deformation of designed steel plates: An optimisation of the side hull structure using the finite element approach
  36. Thermal-strength analysis of a cross-flow heat exchanger and its design improvement
  37. Effect of thermal collector configuration on the photovoltaic heat transfer performance with 3D CFD modeling
  38. Experimental identification of the subjective reception of external stimuli during wheelchair driving
  39. Failure analysis of motorcycle shock breakers
  40. Experimental analysis of nonlinear characteristics of absorbers with wire rope isolators
  41. Experimental tests of the antiresonance vibratory mill of a sectional movement trajectory
  42. Experimental and theoretical investigation of CVT rubber belt vibrations
  43. Is the cubic parabola really the best railway transition curve?
  44. Transport properties of the new vibratory conveyor at operations in the resonance zone
  45. Assessment of resistance to permanent deformations of asphalt mixes of low air void content
  46. COVID-19 lockdown impact on CERN seismic station ambient noise levels
  47. Review Articles
  48. FMEA method in operational reliability of forest harvesters
  49. Examination of preferences in the field of mobility of the city of Pila in terms of services provided by the Municipal Transport Company in Pila
  50. Enhancement stability and color fastness of natural dye: A review
  51. Special Issue: ICE-SEAM 2019 - Part II
  52. Lane Departure Warning Estimation Using Yaw Acceleration
  53. Analysis of EMG Signals during Stance and Swing Phases for Controlling Magnetorheological Brake applications
  54. Sensor Number Optimization Using Neural Network for Ankle Foot Orthosis Equipped with Magnetorheological Brake
  55. Special Issue: Recent Advances in Civil Engineering - Part II
  56. Comparison of STM’s reliability system on the example of selected element
  57. Technical analysis of the renovation works of the wooden palace floors
  58. Special Issue: TRANSPORT 2020
  59. Simulation assessment of the half-power bandwidth method in testing shock absorbers
  60. Predictive analysis of the impact of the time of day on road accidents in Poland
  61. User’s determination of a proper method for quantifying fuel consumption of a passenger car with compression ignition engine in specific operation conditions
  62. Analysis and assessment of defectiveness of regulations for the yellow signal at the intersection
  63. Streamlining possibility of transport-supply logistics when using chosen Operations Research techniques
  64. Permissible distance – safety system of vehicles in use
  65. Study of the population in terms of knowledge about the distance between vehicles in motion
  66. UAVs in rail damage image diagnostics supported by deep-learning networks
  67. Exhaust emissions of buses LNG and Diesel in RDE tests
  68. Measurements of urban traffic parameters before and after road reconstruction
  69. The use of deep recurrent neural networks to predict performance of photovoltaic system for charging electric vehicles
  70. Analysis of dangers in the operation of city buses at the intersections
  71. Psychological factors of the transfer of control in an automated vehicle
  72. Testing and evaluation of cold-start emissions from a gasoline engine in RDE test at two different ambient temperatures
  73. Age and experience in driving a vehicle and psychomotor skills in the context of automation
  74. Consumption of gasoline in vehicles equipped with an LPG retrofit system in real driving conditions
  75. Laboratory studies of the influence of the working position of the passenger vehicle air suspension on the vibration comfort of children transported in the child restraint system
  76. Route optimization for city cleaning vehicle
  77. Efficiency of electric vehicle interior heating systems at low ambient temperatures
  78. Model-based imputation of sound level data at thoroughfare using computational intelligence
  79. Research on the combustion process in the Fiat 1.3 Multijet engine fueled with rapeseed methyl esters
  80. Overview of the method and state of hydrogenization of road transport in the world and the resulting development prospects in Poland
  81. Tribological characteristics of polymer materials used for slide bearings
  82. Car reliability analysis based on periodic technical tests
  83. Special Issue: Terotechnology 2019 - Part II
  84. DOE Application for Analysis of Tribological Properties of the Al2O3/IF-WS2 Surface Layers
  85. The effect of the impurities spaces on the quality of structural steel working at variable loads
  86. Prediction of the parameters and the hot open die elongation forging process on an 80 MN hydraulic press
  87. Special Issue: AEVEC 2020
  88. Vocational Student's Attitude and Response Towards Experiential Learning in Mechanical Engineering
  89. Virtual Laboratory to Support a Practical Learning of Micro Power Generation in Indonesian Vocational High Schools
  90. The impacts of mediating the work environment on the mode choice in work trips
  91. Utilization of K-nearest neighbor algorithm for classification of white blood cells in AML M4, M5, and M7
  92. Car braking effectiveness after adaptation for drivers with motor dysfunctions
  93. Case study: Vocational student’s knowledge and awareness level toward renewable energy in Indonesia
  94. Contribution of collaborative skill toward construction drawing skill for developing vocational course
  95. Special Issue: Annual Engineering and Vocational Education Conference - Part II
  96. Vocational teachers’ perspective toward Technological Pedagogical Vocational Knowledge
  97. Special Issue: ICIMECE 2020 - Part I
  98. Profile of system and product certification as quality infrastructure in Indonesia
  99. Prediction Model of Magnetorheological (MR) Fluid Damper Hysteresis Loop using Extreme Learning Machine Algorithm
  100. A review on the fused deposition modeling (FDM) 3D printing: Filament processing, materials, and printing parameters
  101. Facile rheological route method for LiFePO4/C cathode material production
  102. Mosque design strategy for energy and water saving
  103. Epoxy resins thermosetting for mechanical engineering
  104. Estimating the potential of wind energy resources using Weibull parameters: A case study of the coastline region of Dar es Salaam, Tanzania
  105. Special Issue: CIRMARE 2020
  106. New trends in visual inspection of buildings and structures: Study for the use of drones
  107. Special Issue: ISERT 2021
  108. Alleviate the contending issues in network operating system courses: Psychomotor and troubleshooting skill development with Raspberry Pi
  109. Special Issue: Actual Trends in Logistics and Industrial Engineering - Part II
  110. The Physical Internet: A means towards achieving global logistics sustainability
  111. Special Issue: Modern Scientific Problems in Civil Engineering - Part I
  112. Construction work cost and duration analysis with the use of agent-based modelling and simulation
  113. Corrosion rate measurement for steel sheets of a fuel tank shell being in service
  114. The influence of external environment on workers on scaffolding illustrated by UTCI
  115. Allocation of risk factors for geodetic tasks in construction schedules
  116. Pedestrian fatality risk as a function of tram impact speed
  117. Technological and organizational problems in the construction of the radiation shielding concrete and suggestions to solve: A case study
  118. Finite element analysis of train speed effect on dynamic response of steel bridge
  119. New approach to analysis of railway track dynamics – Rail head vibrations
  120. Special Issue: Trends in Logistics and Production for the 21st Century - Part I
  121. Design of production lines and logistic flows in production
  122. The planning process of transport tasks for autonomous vans
  123. Modeling of the two shuttle box system within the internal logistics system using simulation software
  124. Implementation of the logistics train in the intralogistics system: A case study
  125. Assessment of investment in electric buses: A case study of a public transport company
  126. Assessment of a robot base production using CAM programming for the FANUC control system
  127. Proposal for the flow of material and adjustments to the storage system of an external service provider
  128. The use of numerical analysis of the injection process to select the material for the injection molding
  129. Economic aspect of combined transport
  130. Solution of a production process with the application of simulation: A case study
  131. Speedometer reliability in regard to road traffic sustainability
  132. Design and construction of a scanning stand for the PU mini-acoustic sensor
  133. Utilization of intelligent vehicle units for train set dispatching
  134. Special Issue: ICRTEEC - 2021 - Part I
  135. LVRT enhancement of DFIG-driven wind system using feed-forward neuro-sliding mode control
  136. Special Issue: Automation in Finland 2021 - Part I
  137. Prediction of future paths of mobile objects using path library
  138. Model predictive control for a multiple injection combustion model
  139. Model-based on-board post-injection control development for marine diesel engine
  140. Intelligent temporal analysis of coronavirus statistical data
https://doi.org/10.1515/eng-2021-0050
Keywords for this article
child restraint system; comfort; vertical vibration
Creative Commons
BY 4.0

Articles in the same Issue

  1. Regular Articles
  2. Electrochemical studies of the synergistic combination effect of thymus mastichina and illicium verum essential oil extracts on the corrosion inhibition of low carbon steel in dilute acid solution
  3. Adoption of Business Intelligence to Support Cost Accounting Based Financial Systems — Case Study of XYZ Company
  4. Techno-Economic Feasibility Analysis of a Hybrid Renewable Energy Supply Options for University Buildings in Saudi Arabia
  5. Optimized design of a semimetal gasket operating in flange-bolted joints
  6. Behavior of non-reinforced and reinforced green mortar with fibers
  7. Field measurement of contact forces on rollers for a large diameter pipe conveyor
  8. Development of Smartphone-Controlled Hand and Arm Exoskeleton for Persons with Disability
  9. Investigation of saturation flow rate using video camera at signalized intersections in Jordan
  10. The features of Ni2MnIn polycrystalline Heusler alloy thin films formation by pulsed laser deposition
  11. Selection of a workpiece clamping system for computer-aided subtractive manufacturing of geometrically complex medical models
  12. Development of Solar-Powered Water Pump with 3D Printed Impeller
  13. Identifying Innovative Reliable Criteria Governing the Selection of Infrastructures Construction Project Delivery Systems
  14. Kinetics of Carbothermal Reduction Process of Different Size Phosphate Rocks
  15. Plastic forming processes of transverse non-homogeneous composite metallic sheets
  16. Accelerated aging of WPCs Based on Polypropylene and Birch plywood Sanding Dust
  17. Effect of water flow and depth on fatigue crack growth rate of underwater wet welded low carbon steel SS400
  18. Non-invasive attempts to extinguish flames with the use of high-power acoustic extinguisher
  19. Filament wound composite fatigue mechanisms investigated with full field DIC strain monitoring
  20. Structural Timber In Compartment Fires – The Timber Charring and Heat Storage Model
  21. Technical and economic aspects of starting a selected power unit at low ambient temperatures
  22. Car braking effectiveness after adaptation for drivers with motor dysfunctions
  23. Adaptation to driver-assistance systems depending on experience
  24. A SIMULINK implementation of a vector shift relay with distributed synchronous generator for engineering classes
  25. Evaluation of measurement uncertainty in a static tensile test
  26. Errors in documenting the subsoil and their impact on the investment implementation: Case study
  27. Comparison between two calculation methods for designing a stand-alone PV system according to Mosul city basemap
  28. Reduction of transport-related air pollution. A case study based on the impact of the COVID-19 pandemic on the level of NOx emissions in the city of Krakow
  29. Driver intervention performance assessment as a key aspect of L3–L4 automated vehicles deployment
  30. A new method for solving quadratic fractional programming problem in neutrosophic environment
  31. Effect of fish scales on fabrication of polyester composite material reinforcements
  32. Impact of the operation of LNG trucks on the environment
  33. The effectiveness of the AEB system in the context of the safety of vulnerable road users
  34. Errors in controlling cars cause tragic accidents involving motorcyclists
  35. Deformation of designed steel plates: An optimisation of the side hull structure using the finite element approach
  36. Thermal-strength analysis of a cross-flow heat exchanger and its design improvement
  37. Effect of thermal collector configuration on the photovoltaic heat transfer performance with 3D CFD modeling
  38. Experimental identification of the subjective reception of external stimuli during wheelchair driving
  39. Failure analysis of motorcycle shock breakers
  40. Experimental analysis of nonlinear characteristics of absorbers with wire rope isolators
  41. Experimental tests of the antiresonance vibratory mill of a sectional movement trajectory
  42. Experimental and theoretical investigation of CVT rubber belt vibrations
  43. Is the cubic parabola really the best railway transition curve?
  44. Transport properties of the new vibratory conveyor at operations in the resonance zone
  45. Assessment of resistance to permanent deformations of asphalt mixes of low air void content
  46. COVID-19 lockdown impact on CERN seismic station ambient noise levels
  47. Review Articles
  48. FMEA method in operational reliability of forest harvesters
  49. Examination of preferences in the field of mobility of the city of Pila in terms of services provided by the Municipal Transport Company in Pila
  50. Enhancement stability and color fastness of natural dye: A review
  51. Special Issue: ICE-SEAM 2019 - Part II
  52. Lane Departure Warning Estimation Using Yaw Acceleration
  53. Analysis of EMG Signals during Stance and Swing Phases for Controlling Magnetorheological Brake applications
  54. Sensor Number Optimization Using Neural Network for Ankle Foot Orthosis Equipped with Magnetorheological Brake
  55. Special Issue: Recent Advances in Civil Engineering - Part II
  56. Comparison of STM’s reliability system on the example of selected element
  57. Technical analysis of the renovation works of the wooden palace floors
  58. Special Issue: TRANSPORT 2020
  59. Simulation assessment of the half-power bandwidth method in testing shock absorbers
  60. Predictive analysis of the impact of the time of day on road accidents in Poland
  61. User’s determination of a proper method for quantifying fuel consumption of a passenger car with compression ignition engine in specific operation conditions
  62. Analysis and assessment of defectiveness of regulations for the yellow signal at the intersection
  63. Streamlining possibility of transport-supply logistics when using chosen Operations Research techniques
  64. Permissible distance – safety system of vehicles in use
  65. Study of the population in terms of knowledge about the distance between vehicles in motion
  66. UAVs in rail damage image diagnostics supported by deep-learning networks
  67. Exhaust emissions of buses LNG and Diesel in RDE tests
  68. Measurements of urban traffic parameters before and after road reconstruction
  69. The use of deep recurrent neural networks to predict performance of photovoltaic system for charging electric vehicles
  70. Analysis of dangers in the operation of city buses at the intersections
  71. Psychological factors of the transfer of control in an automated vehicle
  72. Testing and evaluation of cold-start emissions from a gasoline engine in RDE test at two different ambient temperatures
  73. Age and experience in driving a vehicle and psychomotor skills in the context of automation
  74. Consumption of gasoline in vehicles equipped with an LPG retrofit system in real driving conditions
  75. Laboratory studies of the influence of the working position of the passenger vehicle air suspension on the vibration comfort of children transported in the child restraint system
  76. Route optimization for city cleaning vehicle
  77. Efficiency of electric vehicle interior heating systems at low ambient temperatures
  78. Model-based imputation of sound level data at thoroughfare using computational intelligence
  79. Research on the combustion process in the Fiat 1.3 Multijet engine fueled with rapeseed methyl esters
  80. Overview of the method and state of hydrogenization of road transport in the world and the resulting development prospects in Poland
  81. Tribological characteristics of polymer materials used for slide bearings
  82. Car reliability analysis based on periodic technical tests
  83. Special Issue: Terotechnology 2019 - Part II
  84. DOE Application for Analysis of Tribological Properties of the Al2O3/IF-WS2 Surface Layers
  85. The effect of the impurities spaces on the quality of structural steel working at variable loads
  86. Prediction of the parameters and the hot open die elongation forging process on an 80 MN hydraulic press
  87. Special Issue: AEVEC 2020
  88. Vocational Student's Attitude and Response Towards Experiential Learning in Mechanical Engineering
  89. Virtual Laboratory to Support a Practical Learning of Micro Power Generation in Indonesian Vocational High Schools
  90. The impacts of mediating the work environment on the mode choice in work trips
  91. Utilization of K-nearest neighbor algorithm for classification of white blood cells in AML M4, M5, and M7
  92. Car braking effectiveness after adaptation for drivers with motor dysfunctions
  93. Case study: Vocational student’s knowledge and awareness level toward renewable energy in Indonesia
  94. Contribution of collaborative skill toward construction drawing skill for developing vocational course
  95. Special Issue: Annual Engineering and Vocational Education Conference - Part II
  96. Vocational teachers’ perspective toward Technological Pedagogical Vocational Knowledge
  97. Special Issue: ICIMECE 2020 - Part I
  98. Profile of system and product certification as quality infrastructure in Indonesia
  99. Prediction Model of Magnetorheological (MR) Fluid Damper Hysteresis Loop using Extreme Learning Machine Algorithm
  100. A review on the fused deposition modeling (FDM) 3D printing: Filament processing, materials, and printing parameters
  101. Facile rheological route method for LiFePO4/C cathode material production
  102. Mosque design strategy for energy and water saving
  103. Epoxy resins thermosetting for mechanical engineering
  104. Estimating the potential of wind energy resources using Weibull parameters: A case study of the coastline region of Dar es Salaam, Tanzania
  105. Special Issue: CIRMARE 2020
  106. New trends in visual inspection of buildings and structures: Study for the use of drones
  107. Special Issue: ISERT 2021
  108. Alleviate the contending issues in network operating system courses: Psychomotor and troubleshooting skill development with Raspberry Pi
  109. Special Issue: Actual Trends in Logistics and Industrial Engineering - Part II
  110. The Physical Internet: A means towards achieving global logistics sustainability
  111. Special Issue: Modern Scientific Problems in Civil Engineering - Part I
  112. Construction work cost and duration analysis with the use of agent-based modelling and simulation
  113. Corrosion rate measurement for steel sheets of a fuel tank shell being in service
  114. The influence of external environment on workers on scaffolding illustrated by UTCI
  115. Allocation of risk factors for geodetic tasks in construction schedules
  116. Pedestrian fatality risk as a function of tram impact speed
  117. Technological and organizational problems in the construction of the radiation shielding concrete and suggestions to solve: A case study
  118. Finite element analysis of train speed effect on dynamic response of steel bridge
  119. New approach to analysis of railway track dynamics – Rail head vibrations
  120. Special Issue: Trends in Logistics and Production for the 21st Century - Part I
  121. Design of production lines and logistic flows in production
  122. The planning process of transport tasks for autonomous vans
  123. Modeling of the two shuttle box system within the internal logistics system using simulation software
  124. Implementation of the logistics train in the intralogistics system: A case study
  125. Assessment of investment in electric buses: A case study of a public transport company
  126. Assessment of a robot base production using CAM programming for the FANUC control system
  127. Proposal for the flow of material and adjustments to the storage system of an external service provider
  128. The use of numerical analysis of the injection process to select the material for the injection molding
  129. Economic aspect of combined transport
  130. Solution of a production process with the application of simulation: A case study
  131. Speedometer reliability in regard to road traffic sustainability
  132. Design and construction of a scanning stand for the PU mini-acoustic sensor
  133. Utilization of intelligent vehicle units for train set dispatching
  134. Special Issue: ICRTEEC - 2021 - Part I
  135. LVRT enhancement of DFIG-driven wind system using feed-forward neuro-sliding mode control
  136. Special Issue: Automation in Finland 2021 - Part I
  137. Prediction of future paths of mobile objects using path library
  138. Model predictive control for a multiple injection combustion model
  139. Model-based on-board post-injection control development for marine diesel engine
  140. Intelligent temporal analysis of coronavirus statistical data
Sign up now to receive a 20% welcome discount
Institutional Access
How does access work?
Have an idea on how to improve our website?
Please write us.
© 2025 De Gruyter Brill
Downloaded on 20.11.2025 from https://www.degruyterbrill.com/document/doi/10.1515/eng-2021-0050/html
Scroll to top button