·Table of Contents
·Methods and Instrumentation
The Research for Tyre Dynamic Mechanic Feature Simulation Experiment System
Zhao Jiyin, Zhao Jingrong, Huang Ting, Gai Shuang
School of Information Science & Engineering, Jilin University of Technology,
Changchun, China 130025
The tyre dynamic mechanic feature simulation experiment system posed in the paper is an important tool in studying non-static feature. It is a type of mechanic-electronic device, which includes mechanical system, hydraulic system, signal acquisition system and computer control system. The key technique of signal acquisition and computer system design was discussed in the paper in detail.
The tyre mechanic features are important factors affecting operation stability, travelling stationarity, braking safety and vibration of vehicle. The researches have been made focus on the static features and the research of non-static feature is just up to data. However, the real tyre states when travelling are mostly non-static, and the research of the non-static features has more theoretic and realistic value. The tyre dynamic mechanic feature simulation experiment system posed in the paper is an important tool for studying the non-static features in tyre dynamic features in complex condition, including static and non-static features. The main experiment functions are shown as figure 1.
Fig 1: The chief function of the tyre dynamic experiment system|
2.The Technique Thinking of the System
- The signal for measurement only ( includes analog and digital signal ) which output to industrial PC,
- The signal for control only which output to each controller,
- The signal for measurement and control which output to industrial PC and each controller.
3. Signal Measurement System
The signal measurement system of the tyre dynamic experiment system includes the mechanics parameter sensor, the revolve-angle sensor, the signal pre-amplifier, the isolation amplifier and the signal acquisition and process unit. To ensure the reliable and resist interference facility, the analog signal was processed with the linear isolation amplifier and the digital signal with the photo-electronic isolation. The ADC uses the 16 bit, 10ms A/D card to meet the requirement of acquisition precision. Digital signal output to up-set computer and controller in TTL voltage standard and no protocol 16 bit(complement) parallelly.
The tyre was loaded by a four-link mechanism in the tyre dynamic simulation system. The measurement of tyre mechanic parameters is the key link in the experiment system. The measurement of mechanic parameters includes the measurement of six components of force near the ytre and the measurement of the force loaded by up-arm, down-arm and cross arm. The qualification achieved by the tyre dynamic mechanic simulation experimental system was listed in Chart1.
chart 1: The qualification the system achieved|
4. Compute Control System
The computer control system includes the following loops:
- Slide desk longitude movement control;
- Tyre side bias angle control;
- Tyre side leant angle control;
- Tyre vertical load control;
- Tyre longitude force control;
- Tyre break force control.
Computer control system uses DCS in logic structure for central controlling and distributing the danger to improve the reliability and robustness. The system is composed of cards in physical structure in order to be mended. Each loop just finish the local loop parameters' steady control or servo control, the questions about the synchronism and the coordinate among loops are solved by the synchronism signal up-set computer produced. Each loop has the local and the remote method and the remote method is used in system central control, the local method is used in providing manual intervene in special conditions. They are displayed on the panel about both work methods. Each loop has auto and manual working method, the auto method is used in keeping the standard work condition during the experiment, the manual method is available for maintaining the system.
Fig 3: the fundamental structure of each loop controller
Fig 4: The technic solution of general adjuster
5. Data Processing Software
The data processing software is based on WINDOWS 95 operating system. It is composed of several modules as follows:
The function of data processing is shown in Figure5.
- graphic interface control module
- data input and edit module
- parameter identification module
- feature analysis module
- visual graphic module,
- result output module.
Fig 5: the function of data processing software|
The researches have been made focus on the static features. And the research of non-static feature is just up to data. However, the real tyre state on travelling are mostly non-static, and the research of the non-static features has more theoretic value. The success in researching and producting the tyre dynamic mechanic feature simulation experiment system will be steadfast foundation for the studying of tyre non-static feature research.
- Konghui Guo, The maneuvering dynamic theory for automobile , Changchun 1991
- Chen S. Billing S A. Neural networks for nonlinear dynamic system modelling and identification. In : Harris C J. Ed. Advances in Intelligent Control. London : Taylor and Francis, 1994. Chapter4
- Takiguchi T. Improvement of vehicle dynamics by vehicle-speed-sensing four-wheel steering system. SAE Paper 860624,1986