Study on Vibration Characteristics and Human Riding Comfort of a Special Equipment Cab

Abstract

special equipment drivers much suffered from vibration which threatened their physical and mental health. In decree to study the riding ease of a especial equipment cab, a hammer experiment has been carried out on it by acceleration sensors. According to the test results, the natural frequency has been calculated which was compared with the result analysis by the finite element method acting. Next, the equipment operating condition quiz on a flat road was done. The oscillation characteristics of the hale fomite were obtained belated. The results show that the cab vibration and the finite component results agree well, but the natural frequency of the cab is close to the vibration frequency of the homo body. And this is not conducive to long-run operation of the drivers. In decree to improve the homo operational comfort, it is necessary to reduce its natural frequency during the cab structure design serve. The research in this paper can provide avail for the similar human-machine operation comfort study and merchandise design .

1. Introduction

due to the atrocious influence environment, some special engineering equipment dynamic feature and oscillation laws are not researched arsenic clear as other mechanics such as automobiles and trains. therefore, the study of the especial equipment dynamic characteristic along with the vibration law can provide help oneself for the product design and driver ride consolation of such equipment. Vehicle cab is an significant separate of manipulate and riding nowadays. The human safety and comfort are immediately related to oscillation characteristics of the taxi ; frankincense, they have engineering and medical significance for drivers in a biomedical technology field. By far, the researchers of the limited equipment cab shaking are chiefly as follows : Caffaro et alabama. had made ergonomic inquiry on a type of forklift vibration. then, they analyzed the impression of the device active suspended cab on the human torso vibration and did the cogitation of the operators ’ quilt [ 1 ]. Aiming at improving operating conditions, Sun and Zhang had done the low-frequency shaking report of the bulldozer cab vibration ; then, the structure design and improvement schema of the equipment had been proposed [ 2 ]. Xu et aluminum. had established a comprehensive examination model of a cab and an operator ; then, the damping layout way had been researched [ 3 ]. Kang had built a 5-DOF human body model with a cab seat ; then, the vibration control had been studied. Based on the results, the improved social organization seat was carried out to enhance the human body ride comfort [ 4 ]. Tarabini et aluminum. had proposed a high-performance vibration test for the human body in the operation of a special function device, which is of great significance to the survey of the driver and seat safety [ 5 ]. Xiaoxiong had studied the human body vibration physiological parameters which are crucial for the human body and mechanical equipment ergonomics [ 6 ]. Yuezhen et alabama. had analyzed the vibration of human haptic feedback progress which was very helpful in the aerospace personnel comfort field [ 7 ]. Zhang et aluminum. had established a 5-DOF torso sitting side model. then, the vertical shaking characteristics of each share were obtained which provided dynamic design reference book for the human-machine interface system [ 8 ]. Yingjie et aluminum. had studied the depend on comfort of the high-speed railroad track passenger organization and had analyzed the determine of the vibration frequency on the human body ’ s ride. then, the ease evaluation of a human machine can be obtained according to the body reaction [ 9 ]. Chao had studied a specify engineering vehicle driver ride comfort and gave the research condition and key technologies of it nowadays [ 10 ]. Zhiyan had studied the guard and quilt of a structure machinery cab in order to obtain the fomite and personnel operating suitable working environment [ 11 ]. Minglong had made a shaking study on the taxi of a certain type loader. then, the structural purpose had been improved to reduce the taxi shaking which gave the guidance to the comfort improvement of the human soundbox [ 12 ]. Zhang et aluminum. had established a mathematical exemplary of a road vehicle and analyzed the oscillation coupling effect [ 13 ]. Sim et alabama. had evaluated the hydropneumatic and semiactive cab pause drive consolation of agrarian tractors and given a command algorithm for the suspension system [ 14 ]. Zhao et alabama. had built a loanblend model of seat-cab match system for a truck and did the cab suspensions screen. then, the parameters had been identified by the equipment [ 15 ]. Deboli et aluminum. had done the hale body vibration measurement of horizontal and vertical transmissibility of an agricultural tractor seat. ultimately, they had drawn the termination that the roll and pitching effects can be reduced by using particular suspension systems along the horizontal and lateral directions [ 16 ]. Humphreys et aluminum. have investigated the system dynamics which included the human operator and biodynamic feedthrough. then, two methods of compensation for biodynamic feedthrough based on their models had been developed. The results showed that the operators perform better and prefer the vibration-compensating controllers over their non-vibration-compensating counterparts [ 17 ]. Sim et aluminum. had proposed a hydropneumatic suspension applied with the semiactive control method. then, the tease consolation has been predicted by using the vehicle model based on calculator simulation in the end [ 18 ]. Talamonti et alabama. had described a new method acting called “ mirage scenario ” to support formative evaluation of driver alertness or admonition displays for manual of arms and automated tug. And the results showed that no collision avoidance maneuvers were performed ; thereby, it reduced the risk of simulator nausea [ 19 ]. Mahmoodabadi et alabama. have introduced a novel combination of particle teem optimization ( PSO ) and genetic algorithm ( GA ). The hybrid algorithm uses the operators such as mutation, traditional or classical crossing, multiple-crossover, and PSO formula. At the end, the algorithm had been used for the Pareto optimum design of a five-degree of freedom vehicle shaking model. The comparison of the prevail results demonstrated that it has a beneficial solution in the study [ 20 ]. Lepine et aluminum. had proposed to use machine learning to identify shocks present in acceleration signals measured on road vehicles. Next, a machine learning algorithm has been trained to identify shocks buried within road vehicle shaking signals. The results showed that the machine learning algorithm was well more accurate and reliable in identifying shocks than the more common approaches [ 21 ]. Nariman-Zadeh et alabama. had proposed a new multiobjective uniform-diversity genetic algorithm ( MUGA ) called the ε -elimination algorithm. then, it was used for Pareto optimization of a five-degree of freedom vehicle vibration model considering the five at odds functions simultaneously. The results showed that the 5-objective optimization provided more choices for an optimum purpose of a fomite oscillation model [ 22 ]. Burdzik had presented a novel method for research on exposure to nonlinear vibration of passenger car suspension as a nonlinear dynamic system. The advantage of this method is possibilities of precise analysis of chosen frequency bands. then, the influence of dampen of electric shock absorber on exposure to vibration had been discussed [ 23 ]. probabilistic metrics were used for a robust Pareto multiobjective optimum design of five-degree of freedom fomite oscillation model by Jamali et aluminum. The robustness of the design obtained using such a probabilistic approach was shown and compared with that of the blueprint obtained using deterministic access in the end [ 24 ]. Auersch had performed a building complex quantify political campaign including the coincident measurement of fomite, cut, and dirt vibrations during train runs at 16, 25, 40, 63, 80, 100, 125, 140, and 160 kilometers per hour and analyzed the results then [ 25 ]. Lee et aluminum. had introduced a damper that can reduce the amplitude of oscillation in diverse frequency ranges. The electromagnetic damper can change its mood to respond to the vibration excitation at both humble and high frequencies. The results were compared with those of a active damper and indicated that the amplitude of shaking was reduced by 95.6 % when the electromagnetic damper had been implemented on an H/Shaft [ 26 ]. early researchers such as Wenku, Jinwu, Lin Xijun et al., and Lin besides had made contribution to the taxi vibration suppression for such equipment [ 27 – 30 ].

As can be seen in the studies of former researchers, there are different studies in cab structure optimization, oscillation characteristic, and human drive ease of a special equipment. But thus far, the study of particular equipment has not even formed coordinated laws such as vehicles and trains so the research of this special equipment such as the slag pot mailman vibration test is of great significance. In this paper, a special sketch of such alloy slag transportation equipment has been researched ; then, the study of its cab oscillation has been tested aiming at obtaining the oscillation and working moral force characteristics. This newspaper is organized as follows. In section 2, the modal theory is introduced and a finite component model of the cab has been established. In section 3, a flat road test of the particular equipment has been done. In section 4, a discussion between human body and the taxi oscillation is described. finally, segment 5 gives a termination. All of these give aid to the cab social organization optimization, oscillation decrease, and human operating comfort research for engineers and doctors .

2. Cab Modal Theory and Hammering Experiment

The apparent motion equality of the multi-degree-of-freedom arrangement with proportional dampen can be written as In ( 1 ), here in ( 2 ), and are the proportion constants. is the damping matrix. So ( 2 ) has been called proportional muffle equation. and are the mass and awkwardness matrixes, where { } represents vector and [ ] represents matrix. By organize transformation, ( 3 ) can be obtained. In ( 3 ), is the rate mode which can be defined by. By typing ( 3 ) into ( 1 ), then, ( 4 ) is left multiply, and if the modal auxiliary verb shaking orthogonality has been taken into account, ( 5 ) and ( 6 ) can be written as next, In ( 7 ), are respective of the order modal mass, stiffness, and modal muffle coefficients. And furthermore, ( 8 ) can be gotten by In ( 8 ), is the order modal coordinate. Let then. By substituting it into ( 8 ), In ( 9 ) and ( 10 ), is a modal auxiliary verb coordinate vector with amplitude and phase which can be seen as a response of a single-degree-of-freedom system with mass, awkwardness, and dampen, respectively, under the natural process of modal auxiliary verb coerce. is the phase with respect to the excitement power. So the supplanting answer is obtained according to ( 3 ) as seen in ( 11 ) and ( 12 ). Equation ( 12 ) is a modal supreme headquarters allied powers europe in which the proportional syrupy damping system has been considered which can be converted into In ( 13 ), and are the eigenvectors of no damping shaking system which represent the shaking amplitude ratio of each particle at the time of natural frequency. According to the multifreedom modal theory and based on the test equipment, the hammering screen experiment has been carried out in the follow procedure. The test aim is a metal slag transfer vehicle. If the diver operates it during a long time in the taxi, he will have dizziness, nausea, and tinnitus problems. In decree to improve the human-computer interaction and operational ease, the particular vibration trial will include two aspects : ( 1 ) cab interior hammering test which aims at getting its oscillation characteristics. ( 2 ) convention working condition on the two-dimensional road : the function of the examination is to determine whether there is resonance between the vehicle taxi vibration and the consistency with the human physical parameters. furthermore, it can provide aid for the cogitation of human comfort when operating the vehicle. The test speed is 25 kilometers per hour on the 500-meter-long two-dimensional road.

Dynamic data learning instrument called Dewesoft has been adopted as shown in Figure 1. It has 16 input signal and output channels, 6 acceleration channels, and 2 CAN modules. The collect pressure, displacement, strain, and data can be gotten and postprocessed by it. The cab is fixed on a sword plate by means of a shock absorber. then, the ICP acceleration sensors are arranged as shown in Figures 1 and 2. Besides the test, datum is collected by using DS-NET signal collect and processing instrument .

By hammering the around corners of the taxi, the leave raise corner, and the right graze angle, the 3rd accelerator signal time wind under the deck of the cab is shown in Figure 3 .
By the frequency knowledge domain analysis of the cab system, the beginning two order natural frequencies can be obtained : 7.8 Hz and 12.5 Hz. And the dampen ratio is about 0.213. The upright hammer analysis of the cab ’ randomness right front recess is shown in Figure 4 .
By the frequency world analysis of the taxi system, the first gear two order natural frequencies can be obtained : 7.3 Hz and 11.7 Hz. And the muffle proportion is about 0.222. According to the left and right rear corner test results, the receive frequencies of the taxi below 20 Hz are 7.1 Hz, 7.8 Hz, and 12 Hz. In rate to verify the results, a finite element model of the cab has been established as shown in Figure 5. then, the shaking characteristics and the match oscillation modes have been calculated. The cab used Shell63 unit in the finite model. The shock absorber between the taxi and the frame used blend 14 units. then, the beginning four order modes have been calculated then. The natural frequency values are 6.80 Hz, 7.95 Hz, 12.02 Hz, and 12.04 Hz which are in good agreement with the test results .

3. Flat Road Motion Test

The equipment normally works on the bland road so it is of great importance to do the two-dimensional road solve condition test. According to the measuring point arrangement from the test field, the acceleration bespeak data within 0.5 sulfur has been collected. The time knowledge domain data of the frame of reference steel plate ( acceleration sensors 4 and 9 ), under the seat ( acceleration detector 8 ), and the musical instrument panel ( acceleration sensors 1 and 2 ) are shown in Figure 6. Besides the acceleration detector 4, 9, and 8 frequencies, domain curves are shown in Figure 7 .(a) The 4th sensor acceleration of the frame plate
(a) The 4th sensor acceleration of the frame plate(b) The 9th sensor acceleration of the frame plate
(b) The 9th sensor acceleration of the frame plate(c) The 8th sensor acceleration under the cab seat
(c) The 8th sensor acceleration under the cab seat(d) The 2nd sensor acceleration of the frontier dashboard
(d) The 2nd sensor acceleration of the frontier dashboard(e) The 1st sensor acceleration of the rear dashboard
(e) The 1st sensor acceleration of the rear dashboard(a) The 4th sensor acceleration spectrum of the frame plate
(a) The 4th sensor acceleration spectrum of the frame plate(b) The 9th sensor acceleration spectrum of the frame plate
(b) The 9th sensor acceleration spectrum of the frame plate(c) The 8th sensor acceleration spectrum under the cab seat
(c) The 8th sensor acceleration spectrum under the cab seat By analyzing the ensnare plate ( acceleration sensors 4 and 9 ) and under the seat ( acceleration detector 8 ) acceleration spectrum, it can be calculated that each spectrum has a different degree of point at the frequency of 4.8 Hz. This indicates that there exists a natural frequency near the 4.8 Hz of the vehicle. This natural frequency along with the first base three holy order natural frequencies of the cab and the natural frequency vibrations of the driver ’ randomness body part of the organism will resonate if they are like. The happening of rapport will cause unlike physiologic discomforts of the operators .

4. Human Vibration Parameter Comparison and Result Discussion

According to the existing research, the natural frequency of a human-standing torso is about 7.5 Hz, and the frequency of a sitting carriage in the taxi is generally 4–6 Hz. The natural frequency of the chief body parts is shown in postpone 1 .Body partNatural frequency (Hz)The whole body7.5Body torso7–13Head8–12Thoracic cavity4–6Heart5Abdominal cavity6–9Spine10–12Pelvic6 It can be seen from table 1 that the natural frequencies of the homo spine and head are relatively large in all parts. This is because most of these two parts are composed of rigid bodies, and the academic degree of flexibility is relatively little. The frequency of the pectoral cavity and heart is about 5 Hz, relatively humble, because both parts are brawny tissues with a eminent degree of flexibility. The natural frequencies of other parts, such as the pelvic cavity and the abdomen, are in the middle position. therefore, the rapport is likely to occur among the taxi, the whole fomite, and the operator. If the special equipment driver is in the shaking environment for a long-run without command, the motion, urinary, digestive, nervous, and cardiovascular system diseases will lead to physiologic health disease either. thus in regulate to protect the driver ’ s physical and mental health, the shaking of the equipment must be controlled in a fair crop. It is cheeseparing to the natural frequency of the chest of drawers and kernel. therefore, in order to avoid the two parts being affected by rapport, it is necessary to be conclusion to the seat when drive. It can form a system with the seat, so as to improve the natural frequency of the solid vehicle and avoid the self-resonance area. The important parts of the human body vibration frequency are broadly located in about 3 Hz–17 Hz. According to the International Standard ISO 2631 in the erect shaking of the human body, the sensible range is located in 6 Hz–8 Hz. In this range, the EMG and EEG energies will have a substantial increase due to the shaking. When the body oscillation frequency reaches 10 Hz–20 Hz, the skeletal muscle will have a compressed contraction. then, it will suppress the tendon automatic. According to the test of this particular equipment, there is a lifelike frequency near 4.8 Hz of the car. The foremost three order frequencies of the vehicle taxi are 7.1 Hz, 7.8 Hz, and 12 Hz which are conclude to the equipment normal oeuvre condition frequency and the driver ’ s physical parameters. The natural frequencies of the head and spine are closer to them. consequently, head fixtures can be added in the cab seat, and try to put the head in the fixed slot adenine far as possible, and the back of the consistency should be close to the seat either. It can efficaciously avoid the rapport frequency image by making a whole system with the seat. last, the drivers ’ discomfort can be decreased to the utmost degree.

5. Conclusion

From the “ people-oriented ” concept, in order to reduce the operator ’ south long-run operation of the special equipment, which may cause physical and genial health damage, a extra equipment cab organization hammer quiz and the wholly vehicle flat road motion test have been done. The stopping point can be drawn as follows : ( 1 ) By the hammering test analysis of the equipment cab, the first 3 order natural frequencies of the organization are about 7 Hz, 7.8 Hz, and 12 Hz. Besides, the damping ratio is approximately 21 %, which is close to the oscillation medium scope of the human torso. ( 2 ) The cab shock absorber absorber has a separate of the vibration suppression effect of the flat road random excitement which improves the driver ’ mho operating comfort to some certain extent. The natural frequency of the taxi system is higher than that of the whole vehicle. But the damping pad normally works at a low frequency near the natural frequency of the whole vehicle which can not play a good damp effect for a long time. At the lapp time, the driver and the seat are in direct contact so the homo soundbox is in the most uncomfortable frequency oscillation range. ( 3 ) In club to improve the comfort of the driver, it is necessity to reduce the natural frequency of the cab structure in the design march. furthermore, when the cab frequency has been reduced, the shock absorber can work efficiently which is of avail for the working safety of the car besides. ( 4 ) The lower the whole fomite and the taxi natural frequency the more conducive for the operators to avoid the body vibration uncomfortable area. So the equipment fully cargo capacity and cab structure design should be considered at the lapp time .

Conflicts of Interest

The authors declare that they have no conflicts of pastime .

Acknowledgments

This work was supported by “ Human machine dynamic characteristics of multi degree of freedom rehabilitation displacement device ” ( 172102310542 ), “ Multi-DOF Rehabilitation patient transfer device dynamics characteristic and human-machine safety comfort inquiry ” ( 505140 ), “ Human comfort discipline by elevator fare based on multi-body dynamics ” ( no. 2015KYJH33 ), the Natural Science Foundation of Henan state ( 2014GGJS-096 and 152102310357 ), Abnormal shear stress mediated formula of PCSK9 in atherosclerotic brass cells ( 152102210339 ), and Effect of mechanical factors on protein expression in atherosclerotic plaque cells ( 15a180056 ) .

informant : https://nutritionline.net
Category : Healthy