A vehicle control system which can ensure high reliability, real-time processing, and expandability with a simplified ECU configuration and a low cost by backing up an error through coordination in the entire system without increasing a degree of redundancy of individual controllers beyond the least necessary level. The vehicle control system comprises a sensor controller for taking in sensor signals indicating a status variable of a vehicle and an operation amount applied from a driver, a command controller for generating a control target value based on the sensor signals taken in by the sensor controller, and an actuator controller for receiving the control target value from the command controller and operating an actuator to control the vehicle, those three controller being interconnected via a network. The actuator controller includes a control target value generating unit for generating a control target value based on the sensor signals taken in by the sensor controller and received by the actuator controller via the network when the control target value generated by the command controller is abnormal, and controls the actuator in accordance with the control target value generated by the control target value generating unit.

Vehicle Control System

In order to reliably assist a driver in emergency detour steering without causing a jerking forward motion of the vehicle during normal operation, a vehicle motion control device includes: a risk potential estimator that estimates a risk potential of a vehicle based on input external information and vehicle information; a vehicle longitudinal motion controller that generates a longitudinal motion control command of the vehicle based on a vehicle lateral jerk and a predetermined gain; and a gain adjustor that adjusts the gain, in which the gain adjustor adjusts the gain based on the risk potential estimated by the risk potential estimator.

Vehicle motion control device

A stabilizing observer-based control algorithm for an in-wheel-motored vehicle is proposed, which generates direct yaw moment to compensate for the state deviations. The control scheme is based on a fuzzy rule-based body slip angle (beta) observer. In the design strategy of the fuzzy observer, the vehicle dynamics is represented by Takagi-Sugeno-like fuzzy models. Initially, local equivalent vehicle models are built using the linear approximations of vehicle dynamics for low and high lateral acceleration operating regimes, respectively. The optimal beta observer is then designed for each local model using Kalman filter theory. Finally, local observers are combined to form the overall control system by using fuzzy rules. These fuzzy rules represent the qualitative relationships among the variables associated with the nonlinear and uncertain nature of vehicle dynamics, such as tire force saturation and the influence of road adherence. An adaptation mechanism for the fuzzy membership functions has been incorporated to improve the accuracy and performance of the system. The effectiveness of this design approach has been demonstrated in simulations and in a real-time experimental setting.

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Direct Yaw-Moment Control of an In-Wheel-Motored Electric Vehicle Based on Body Slip Angle Fuzzy Observer

A vehicle stability enhancement control algorithm for a four-wheel-drive hybrid electric vehicle (HEV) is proposed using rear motor driving, regenerative braking control, and electrohydraulic brake (EHB) control. A fuzzy-rule-based control algorithm is proposed, which generates the direct yaw moment to compensate for the errors of the sideslip angle and yaw rate. Performance of the vehicle stability control algorithm is evaluated using ADAMS and MATLAB Simulink cosimulations. HEV chassis elements such as the tires, suspension system, and steering system are modeled to describe the vehicle's dynamic behavior in more detail using ADAMS, whereas HEV power train elements such as the engine, motor, battery, and transmission are modeled using MATLAB Simulink with the control algorithm. It is found from the simulation results that the driving and regenerative braking at the rear motor is able to provide improved stability. In addition, better performance can be achieved by applying the driving and regenerative braking control, as well as EHB control.

Vehicle Stability Enhancement of Four-Wheel-Drive Hybrid Electric Vehicle Using Rear Motor Control

FIELD: transportSUBSTANCE: vehicle control system is proposed which is made capable to determine vehicle behaviour or driving preference of driver In the control system, acceleration value used to determine vehicle behaviour or driving preference is obtained based on weighted value of vehicle actual longitudinal acceleration determination and weighted parameter The parameter is varied due to operation of vehicle motive power increment performed by driver Weight factor of parameter is decreased in case when weight factor of longitudinal acceleration determination value is increased, and the weight factor of parameter is increased in case when weight factor of longitudinal acceleration determination value is decreased The system is made capable to control any of characteristics of gear shifting, motive power, steering and suspensionEFFECT: determination of driving preference of driver and adjustment of control characteristic according to driver's intention6 cl, 7 dwg

Vehicle control system

A control input for drive/brake force operation of one or more specific wheels, i.e. a k-th wheel, out of a plurality of wheels of a vehicle is determined to satisfy the requirements for the relation between a road surface reaction acting on the k-th wheel from the road surface depending on the detection values or estimated values of the road surface reaction and the frictional characteristics of the k-th wheel, a feedback control input concerning the drive/brake force of the k-th wheel for bringing the difference between the quantity of state and a model quantity of state of the vehicle close to 0, a feed forward control input of drive/brake force dependent on a drive controlled variable by the driver of the vehicle, and a control input for drive/brake force operation of the k-th wheel. Consequently, actual motion of the vehicle can be controlled to a desired motion while taking account of the characteristics of road surface reaction acting to the wheel from the road surface appropriately.

Controller of vehicle

A driving/braking force manipulation control input of a k-th wheel, which denotes one or more specific wheels among a plurality of wheels of a vehicle, is determined such that a required condition concerning a relationship among a road surface reaction force that may act from a road surface on the k-th wheel on the basis of the detected values or estimated values of a side slip angle and a friction characteristic of the k-th wheel, a feedback control input related to the driving/braking force of the k-th wheel for bringing a difference between a state amount of the vehicle and a reference state amount close to zero, a driving/braking force feedforward control input based on a drive manipulated variable supplied by a driver of the vehicle, and a k-th wheel driving/braking force manipulation control input is satisfied. This arrangement makes it possible to properly control a motion of an actual vehicle to a desired motion while properly considering the characteristics of a road surface reaction force acting from a road surface on a wheel.

Vehicle Control Device

To enhance both vehicle stability and steerability, vehicle dynamic parameters such as vehicle side slip angle, road friction coefficient and tire side forces were precisely estimated in real time. Utilizing four wheel slip control, a logic for optimizing vehicle dynamics was formulated. Tests on ice- and snow-covered roads demonstrated the effectiveness of the control, and confirmed the validity of the logic.

Enhancements in vehicle stability and steerability with slip control

A road surface frictional coefficient estimating apparatus has a device for determining a first estimated value of a yaw moment Mnsp_estm generated at an NSP of a vehicle due to the resultant force of road surface reaction forces acting on each wheel by using, for example, a frictional coefficient estimated value that has been determined, and a device for determining a second estimated value of a yaw moment Mnsp_sens generated at the NSP from the observed value of motional state amounts defining an inertial force moment at the NSP. The increasing/decreasing manipulated variable of the frictional coefficient estimated value is sequentially determined on an error (Mnsp_sens−Mnsp_estm) such that the error is converged to zero, and the road surface frictional coefficient is updated on the basis of the increasing/decreasing manipulated variable.

Road surface frictional coefficient estimating apparatus

In a vehicle motion control system based on a target yaw rate scheme, a brake force computing unit brakes an outer front wheel in a controlled manner when a sign of the yaw rate has changed and the yaw rate increment has become equal to or greater than a threshold value after a counter steer action has been detected and the vehicle body slip angle has become equal to or greater than a threshold value Thus, suppose that a vehicle travels a winding road and a counter steer action is taken If the vehicle body slip angle and actual yaw rate increment exceed threshold values, the outer front wheel is braked Therefore, even when the vehicle body slip angle reaches a maximum value and an attempt is made to reduce it again by a counter steer action in a similar manner as a swinging pendulum, because the increases in the yaw rate and actual yaw rate increment are predicted and monitored before the vehicle body slip angle reaches its maximum value, the vehicle is enabled to travel in a stable fashion

Hiroyuki Urabe

Papers

Controller of vehicle

Vehicle Control Device

Enhancements in vehicle stability and steerability with slip control

Road surface frictional coefficient estimating apparatus

Vehicle motion control system