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On line estimation of tyre characteristics for vehicle control
Abstracts/JSAE Review 16 (1995) 211-222 systems are currently manufactured and usable for such requirements, considering their performance and cost. In the first part, this paper describes the method of modelling, using a knowledge model and a representation model. These models are obtained, respectively, with bond graphs and through identification. The wheel-road interface is represented by Pacejka's model. We then develop the simulation methods with our software called PROUESSE [HASS 91] and the methods for designing braking algorithms. Special emphasis is put on this important field. In the second part, we explain how the models we developped are used for designing a new braking system. This braking system can be described as a "drive-by-wire" system. In the third, part we present the results which can be obtained with different control algorithm. We examine classic control, adaptive control and fuzzy logic. 9438754 Dynamic aspects of a calliper brake system Jean-Marc Perronne, Marc Rennet, G6rard L~on Gissinger (M.I.A.M./France), pp. 491-496, 17 figs., 5 refs. The present evolution of regulated braking requires the knowledge and control of dynamic parameters of the vehicle during the braking process. The investigation we propose is based on on-line strain measurement of the braking torque with in situ signal processing. Investigating the mechanical environment of a vehicle, we found that the strains to which a bracket anchor was subjected, could to a certain extent, represent the braking torque. The braking torque gives a real picture of the braking effects, the deceleration of the vehicle, the limits of skid resisting properties and the behaviour of the calliper system during the process. Using a computer model, we placed strain gauges on the bracket anchor. To avoid any interference that might affect a low voltage signal, the signal was conditioned in-situ. Tests were carried out on a vehicle. This paper shows different braking effects and signals, respectively from the torque sensor and from aceelerometers giving the accelerations of the passenger-car-body.
9438763 Air-Fuel Ratio Characteristics of Engine Drivetrain Control System Using Electronically Controlled Throttle Valve and Air Flow Meter Yoshishige Ohyama (Hitachi Ltd./Japan), pp. 497-502, 9 figs., 1 tables, 31 refs. Air-fuel ratio characteristics which exert a large influence on exhaust emissions and driveability were investigated for an engine drivetrain control system. In the system, the driving torque, one of the main variables for vehicle dynamic control with spark ignition engines can be controlled by using an electronically controlled throttle valve with air flow meters and an electronically controlled transmission. The control algorithms of the throttle valve against the target torque which is given by accelerator position and road surface conditions were clarified so as to reduce the fluctuations in the output torque and the air-fuel ratio during acceleration and braking on both high and low traction roads. 9438772 Effect of the Concentration of Electrolyte Impurities in Ice on the Characteristics of Studless Tires Ken'ichi Shimizu, Mitsuya Nihei, Emmanuelle Douce (Aist, Miti/Japan), pp. 503-508, 14 figs., 3 tables, 3 refs. Tire performance on an icy road depends on the characteristics of the ice involved. Tests on different types of test tracks lead to different results. The conductivity of melted ice has been proposed as a scale for classifying the characteristics of ice, which affect the properties of tires in their operation on ice. This scale indicates well the properties of tires in their operation on ice in relation to the concentration of the various electrolyte impurities in the ice. The electrical resistivity of the ice surface has also been proposed as a quick scale, and the principles behind this are also discussed in this paper. 9438781 Road Surface Recognition Method Using Optical Spatial Filter Tetsuya Uno, Yasunobu Sakai, Junichi Takagi, Tsukasa Yamashita (Omron Corp./Japan), pp. 509-514, 9 figs., 2 tables, 6 refs.
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A novel road surface recognition method using an optical spatial filter is proposed. The optical system of a non-contact ground speed sensor with the spatial filter was adopted for the recognition. The road surfaces such as gravel, asphalt and snow were experimentally discriminated with a spatial frequency spectrum and intensity of regularly reflected light from the surface. Accordingly, the optical sensor which can detect both ground speed and a kind of road surface should be realized by means of the proposed method. 9438790 Estimation of Tyre Friction for Enhanced ABS-Systems U.W. Kiencke, A. Daiss (University of Karlsruhe/Germany), pp. 515520, 13 figs., 6 refs. In order to enhance ABS braking or to improve chassis control, an intelligent algorithm for determining the actual driving situation is necessary. Estimation of friction coefficients together with measurements of a vibrating gyroscope can provide the necessary information. The friction coefficients are estimated during acceleration or braking, where three different methods are presented. By these approaches an enhanced ABS braking function has come within reach. Further work must however be done. 9438808 On Line Estimation Of Tyre Characteristics For Vehicle Control W.R. Pasterkamp, H.B. Pacejka (Delft University of Technology/The Netherlands), pp. 521-526, 7 figs., 8 refs. Vehicle control that improves manoeuvrability and thereby safety of vehicles under slippery road conditions requires continuously updated estimates of the non-linear tyre characteristics and the friction between tyre and road. A new on-line estimation method, based on recognition of the pneumatic trail, is proposed. A rather inexpensive measurement system is mounted in the vehicle front wheel suspension that identifies the forces and moments acting on the tyre. In conjunction with a database of previous measurements, tyre characteristics and friction between tyre and road can be estimated. The design of the estimator is complicated by camber, residual forces and moments, combined slip of the tyre and dynamic behaviour of tyre and suspension.
9438817 Application of Neural Networks in Real Time Identification of Dynamic Structural Response and Prediction of Road-Friction Coefficient pt from Steady State Automobile Response Chinmoy Pal, Ichiro Hagiwara, Hideki Inoue (Nissan Motor Co., Ltd./Japan), Shin Morishita (Yokohama National University/Japan), pp. 527-532, 8 figs., 7 tables, 11 refs. Most of the existing control techniques applied on automobile field is based on the linear model of the relevant dynamic system. However, in spite of the increasing demand of more sophisticated vehicles, few researches are directed in understanding and predicting the non-linear response caused by non-predictable operating conditions such as the variation of suspension characteristics due to wear and tear, the frictional coefficient of road and etc. In this paper, we applied the neural-network based identification technique to predict the structural response of a non-linear system and applied it to forecast the frictional coefficient of the road. Numerical results indicate promising future applications on actual on-board control system likely to be implemented in the near future. 9438826 Estimation of Road Surface Conditions Using Wheel Speed Behavior Masayoshi Ito, Kenneth Yoshioka, Takeshi Saji (Mitsubishi Motors Corp./Japan), pp. 533-538, 12 figs., 1 table, 3 refs. As a result of the need for higher vehicle performance, vehicle control systems, such as the traction control system, which can perform adequately over most road surfaces have been developed. However, the additional ability to estimate the friction coefficient between the tire and road-surface enables optimal adjustment to varying road conditions thereby improving system performance. This paper presents a method by which road surface conditions can be estimated using the wheels' rotational behavior. By monitoring the difference in speed between the driven
9438763 Air-Fuel Ratio Characteristics of Engine Drivetrain Control System Using Electronically Controlled Throttle Valve and Air Flow Meter Yoshishige Ohyama (Hitachi Ltd./Japan), pp. 497-502, 9 figs., 1 tables, 31 refs. Air-fuel ratio characteristics which exert a large influence on exhaust emissions and driveability were investigated for an engine drivetrain control system. In the system, the driving torque, one of the main variables for vehicle dynamic control with spark ignition engines can be controlled by using an electronically controlled throttle valve with air flow meters and an electronically controlled transmission. The control algorithms of the throttle valve against the target torque which is given by accelerator position and road surface conditions were clarified so as to reduce the fluctuations in the output torque and the air-fuel ratio during acceleration and braking on both high and low traction roads. 9438772 Effect of the Concentration of Electrolyte Impurities in Ice on the Characteristics of Studless Tires Ken'ichi Shimizu, Mitsuya Nihei, Emmanuelle Douce (Aist, Miti/Japan), pp. 503-508, 14 figs., 3 tables, 3 refs. Tire performance on an icy road depends on the characteristics of the ice involved. Tests on different types of test tracks lead to different results. The conductivity of melted ice has been proposed as a scale for classifying the characteristics of ice, which affect the properties of tires in their operation on ice. This scale indicates well the properties of tires in their operation on ice in relation to the concentration of the various electrolyte impurities in the ice. The electrical resistivity of the ice surface has also been proposed as a quick scale, and the principles behind this are also discussed in this paper. 9438781 Road Surface Recognition Method Using Optical Spatial Filter Tetsuya Uno, Yasunobu Sakai, Junichi Takagi, Tsukasa Yamashita (Omron Corp./Japan), pp. 509-514, 9 figs., 2 tables, 6 refs.
221
A novel road surface recognition method using an optical spatial filter is proposed. The optical system of a non-contact ground speed sensor with the spatial filter was adopted for the recognition. The road surfaces such as gravel, asphalt and snow were experimentally discriminated with a spatial frequency spectrum and intensity of regularly reflected light from the surface. Accordingly, the optical sensor which can detect both ground speed and a kind of road surface should be realized by means of the proposed method. 9438790 Estimation of Tyre Friction for Enhanced ABS-Systems U.W. Kiencke, A. Daiss (University of Karlsruhe/Germany), pp. 515520, 13 figs., 6 refs. In order to enhance ABS braking or to improve chassis control, an intelligent algorithm for determining the actual driving situation is necessary. Estimation of friction coefficients together with measurements of a vibrating gyroscope can provide the necessary information. The friction coefficients are estimated during acceleration or braking, where three different methods are presented. By these approaches an enhanced ABS braking function has come within reach. Further work must however be done. 9438808 On Line Estimation Of Tyre Characteristics For Vehicle Control W.R. Pasterkamp, H.B. Pacejka (Delft University of Technology/The Netherlands), pp. 521-526, 7 figs., 8 refs. Vehicle control that improves manoeuvrability and thereby safety of vehicles under slippery road conditions requires continuously updated estimates of the non-linear tyre characteristics and the friction between tyre and road. A new on-line estimation method, based on recognition of the pneumatic trail, is proposed. A rather inexpensive measurement system is mounted in the vehicle front wheel suspension that identifies the forces and moments acting on the tyre. In conjunction with a database of previous measurements, tyre characteristics and friction between tyre and road can be estimated. The design of the estimator is complicated by camber, residual forces and moments, combined slip of the tyre and dynamic behaviour of tyre and suspension.
9438817 Application of Neural Networks in Real Time Identification of Dynamic Structural Response and Prediction of Road-Friction Coefficient pt from Steady State Automobile Response Chinmoy Pal, Ichiro Hagiwara, Hideki Inoue (Nissan Motor Co., Ltd./Japan), Shin Morishita (Yokohama National University/Japan), pp. 527-532, 8 figs., 7 tables, 11 refs. Most of the existing control techniques applied on automobile field is based on the linear model of the relevant dynamic system. However, in spite of the increasing demand of more sophisticated vehicles, few researches are directed in understanding and predicting the non-linear response caused by non-predictable operating conditions such as the variation of suspension characteristics due to wear and tear, the frictional coefficient of road and etc. In this paper, we applied the neural-network based identification technique to predict the structural response of a non-linear system and applied it to forecast the frictional coefficient of the road. Numerical results indicate promising future applications on actual on-board control system likely to be implemented in the near future. 9438826 Estimation of Road Surface Conditions Using Wheel Speed Behavior Masayoshi Ito, Kenneth Yoshioka, Takeshi Saji (Mitsubishi Motors Corp./Japan), pp. 533-538, 12 figs., 1 table, 3 refs. As a result of the need for higher vehicle performance, vehicle control systems, such as the traction control system, which can perform adequately over most road surfaces have been developed. However, the additional ability to estimate the friction coefficient between the tire and road-surface enables optimal adjustment to varying road conditions thereby improving system performance. This paper presents a method by which road surface conditions can be estimated using the wheels' rotational behavior. By monitoring the difference in speed between the driven