2016 International Conference on Materials, Information, Mechanical, Electronic and Computer Engineering (MIMECE 2016) ISBN: 978-1-60595-420-2

Research on Key Parameters of Tractor Driving Comfort Based on CATIA

Wei Di

ABSTRACT

Tractor is a widely used in the field of China's agricultural production of

agricultural machinery. The operating environment is complex, poor working conditions, resulting in the labor intensity of the driver. A driver driving a tractor in the uncomfortable state, various parts of the body in a negative state, resulting in unresponsive, errors in judgment, the operation is not accurate. Therefore, research on the key parameters affecting the comfort of tractor drivers, which lays a good foundation for the reasonable arrangement of the operating components and the design of the seat comfort.

1.THE TRACTORD DRIVER SITTING POSTURE MODEL BUILDING

GB/T10000-1988 “Chinese adult body size” is an important man-machine

engineering technical standards. This paper build the driver human model in China based on the body size of GB/T10000-1988. Table 1 is the part of GB/T10000-1988. Meeting the needs of all the tractor driver is impossible on the design, which must be taken to meeting the majority driver size data as the basis[1]. With the 5% percentile on behalf of short stature, the 50% percentile on behalf of medium stature, the 95% percentile on behalf of tall. This paper only consider the adaptive comfort simulation the majority of drivers, so only use the 50% percentile of medium height driver establishment the human body model.

In the CATIA there have not human body model of the Chinese people, so it is necessary to input the Chinese standard of human body model data[2]. In addition, the measurement items between established model of the human body in CATIA and GB/T10000-88 standard is not exactly the same (the same item has 11), as shown in table 2.

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Wei Di, Jilin Agricultural University, 2088 XinCheng Street, Changchun City of Jilin Province, China

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GB/T10000-1988 is the human body data measured in 1988. The body size changes in China during the period[3]. This paper calculate the body size growth rate. GB/T10000-1988 is close to the year of the ISO3411:1985 standard measurement. This paper compares the ISO3411:1985 and ISO3411:2007, than calculate the body size growth rate.

Table I. Main dimensions of chinese adults. （unit: mm）

Male（18-60years） Female（18-55 years）

percentile 5 10 50 90 95 5 10 50 90 95 height 1583 1604 1678 1754 1775 1484 1503 1570 1640 1659 weight 48 50 59 70 75 42 44 52 63 66 upper arm length

289 294 313 333 338 262 267 284 303 312

forearm length

216 220 237 253 258 193 198 213 229 234

thigh length

428 436 465 496 505 402 410 438 467 476

leg length 338 344 369 396 403 313 319 344 370 375 Because the measurement project of the human body model in CATIA with ISO

standard and GB/T10000-1988 standard are not exactly the same. Therefore, this paper find common measurement items between three standards, then gather data in each standard. By comparison of data aggregation can be calculated to measure the value of the growth rate. Using the growth rate modify the corresponding Chinese human data, and get a group of China human data.

Table II. CATIA measurement items with the same measurement items in the GB/T10000-88 standard.

code Size name 50 percentile Chinese male (1988)

50 percentile Chinese female (1988)

us24 hip 87.5cm 90cm us33 chest breadth 28cm 26cm us34 chest measurement 86.7cm 82.5cm us37 chest depth 21.2cm 19.9cm us51 Horizontal foot width 9.6cm 8.8cm us52 foot length 24.7cm 22.9cm us61 head breadth 15.4cm 14.9cm us63 head length 18.4cm 17.6cm us66 Standing hip width 30.6cm 31.7cm us79 Sitting shoulder height 59.8cm 55.6cm us115 Thigh circumference 73.5cm 77.2cm GB/T10000-1988 is the human body data measured in 1988. The body size

changes in China during the period[3]. This paper calculate the body size growth rate. GB/T10000-1988 is close to the year of the ISO3411:1985 standard measurement. This paper compares the ISO3411:1985 and ISO3411:2007, than calculate the body size growth rate. Because the measurement project of the human body model in CATIA with ISO standard and GB/T10000-1988 standard are not exactly the same. Therefore, this paper find common measurement items between three standards, then

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gather data in each standard. By comparison of data aggregation can be calculated to measure the value of the growth rate. Using the growth rate modify the corresponding Chinese human data, and get a group of China human data.

According to the formula(1), calculate standard deviation σ, then get the calculation results K=1.645. Making use of average value and standard deviation, it can write a 2007 human body data in the model file.

XP K X (1) Keyword for the preparation of the human body data model file: MEAN_ STDEVM() MEAN_ STDEVF() CORR M() CORR F() The above data recorded in the notepad file, named for Chinese.sws and save. In

the CATIA main menu click options, select custom crowd section of human body measurement tag in the menu bar, click the Add tag will be open Chinese.sws file. If the file read successful, the corresponding population will be added to the list. After add the successful in the human work platform of CATIA, click Insert a New Manikin button can establish the appropriate human model. As shown in Figure 1.

Figure 1. Chinese human body model established in CATIA. 2. TRACTOR CAB SIZE

In this paper size of the tractor cab are referenced by GB/T 24660.1-2009 “agricultural and forestry tractor driver seat technical specifications”, GB/T 24660.2-2009 “farm tractor seat occupant”, GB/T6238-2004 “agricultural tractor driving room doorway, emergency exits and the driver's working position and size”.

The standard size of the above tractor cab in the CATIA set the parameters of the cab. As shown in Figure 2 for the CATIA tractor cab parameters set menu bar.

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Figure 2. CATIA cab parameters set menu bar. 3.THE HUMAN BODY EACH JOINT COMFORT MODEL BUILDING

Driver or passenger comfort is a very important performance index of the automobile body layout. In order to reduce the driver's fatigue, it is necessary to satisfy the requirements of body comfortable posture, which is the basis of the designs of the human body and the seat[4]. The study shows that the joint angle has a very important influence on the subjective feelings of driver comfort. There are also some other factors that may affect the comfortable feeling, such as the duration of the sitting position, and so on[5].

Tractor driver driving comfort is related with the human body joint angles to determine the position. Therefore, it can be in accordance with the comfortable joint angle fitting localization of Chinese human body size model. In this paper, the 50th percentile of the human body size model is simulated, and its comfort is evaluated. Figure 3 and table 3 introduced the driver in the comfortable pose major joint angle adjustment range.

Figure 3. The comfortable position of the driver.

Table III. Joint angle range of human body in comfortable sitting position.

α1 α2 α3 α4 α5 α6 α7 20º-30º 95º-120º 95º-135º 78º-105º 0º-50º 80º-170º 170º-190º

In the human body model posture analysis module of CATIA , the motion range of

each joint angle is divided using the preferred angle editor[6]. After diving the CATIA system can on the current position of the whole and partial evaluation. In this module and then click the edit preferred angle button, it found angles in the human body model corresponding to α1-α7 of table 3. The motion range of each joint angle divided

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into two aspects, one kind is falling in a the comfort area, with green, the other kind is falling in a comfortable outside of the region, with red. A joint angle range adjustment, can simulate different driving the posture, as shown in Figure 4.

Figure 4. Driver's joint angle adjustment model in CATIA. 4. BASED ON THE CATIA TRACTOR DRIVER COMFORT SIMULATION RESULTS ANALYSIS

There are 27 tractors cab comfort simulation parameters in CATIA. These parameters are divided into four categories: seat arrangement parameters, steering wheel arrangement parameters, pedal arrangement parameters, foot positioning parameters. This paper choose six key parameters of driver sitting posture[7]. The six parameters as shown in the following table 4. These key parameters are simulation and analysis. This paper satisfy the tractors cab design requirements, and at the same time, adjust a parameter range (the parameter range to satisfying the national standard), the parameters of the human body each joint are analyzed, and the driver total comfort effect are analyzed[8].

Open the driving environment definition dialog, in order to entering the 21 fixed parameter values, the range of above 6 parameters were adjusted. In the model of the human body posture analysis module to open the model of the human body posture assessment analysis dialog, the system provides two posture analysis display mode, one is the list type, as shown in Figure 5. Another one is the chart type, as shown in Figure 6. In the list type result (evaluation) is expressed as a percentage, it represent degree of comfort posture. The higher score, the more comfortable.

Table Ⅳ. Key parameters and reference range of the driver’s sitting posture comfort.

serial number

key parameters of driver's sitting posture comfort

code in CATIA reference range of national standard

1 Cushion angle A27 3º-12º 2 Heel point steering wheel distance L11 350-525（cm） 3 Heel from the height of the steering wheel H17 555-765（cm） 4 Driver's foot angle A48-1 30º-60º 5 Steering wheel angle A18 20º-30º 6 Driver's thigh and seat angle A19 0º-12º

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Figure 5. Posture evaluation of list type. Figure 6. Posture evaluation of chart type. 5. CONCLUSION

The analysis results of the P50 percentile male and female parameters were as follows:

(1)with the increase of the cushion angle A27, the total comfort of the human body is also increased.

(2)with the increase of heel from the height of the steering H17, upper arm and hands of the decline in comfort, human total comfort also decreased.

(3)with the increase of heel point steering wheel distance L11, feet, forearm, leg comfort reduce, human total comfort also decreased.

(4)with the increase of driver's thigh and seat angle A19, the foot, forearm, upper arm comfort slightly decreased, the total comfort of the human body also decreased.

(5)with the increase of steering wheel angle A18, women human total comfort also decreased. 24º, 29º reduced to comfort the minimum. P50 percentile of male human total comfort is normal distribution.

(6) with the increase of driver's foot angle A48-1, the female left leg comfort increase, the left thigh comfort increase, the human body total comfort also increase, and the male human body comfort is normal distribution.

This paper has Jilin Agricultural University doctoral start-up fund support. REFERENCES 1. Zixue Du. 2011. Automotive Ergonomics. China Machine Press, pp. 28-29. 2. Enrong Mao, Hong Zhang, and Zhenghe Song. 2007. Vehicle Ergonomics. Beijing Institute of

Technology press, pp. 17-18. 3. Bo Chen, Dongyi Li, and Jiaxin Zhang. 2011. “The Research of Chinese Adult Human Body Model

Based on V5 CATIA,” Human Ergonomics, 17(1): 51-54. 4. Heiner Bubb, and Stefan Estermann. 2000. “ Influence of Forces on Comfort Feeling in

Vehicles,” presented at SAE Paper, January 18- January 23, 2171. 5. Yong Chen, Guoxian Wu, and Zhongming Zhao. 2009. “Human Factors Analysis and Optimization

Based on CATIA Simulation Modeling,” Journal of System Simulation, 21(14): 4540-4553. 6. Dengfeng Wang, Bo Huang. CATIA V5 Machinery (Automotive) Product CAD/CAE/CAM Full

Mastery Tutorial. China Communications Press, pp. 432. 7. Jindong Ren. Automotive Ergonomics. Beijing University Press, pp. 256-258. 8. Haisha Liang, Qian Zhang, and Sihong Zhu. 2012. “Ergonomics Research of Tractor Cab Based

on Human Body Model,” Tractor and Farm Transporter, 20(1): 19-22.

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