Hiroshi Mouri

Design of lane-keeping control with steering torque input

This paper presents the dynamical modeling and identification of a vehicle in which steering torque is controlled, not the steering angle. A lane-tracking control system has been designed on the basis of H2 control theory. The robustness of this system against the nonlinearity of the vehicle was confirmed by mu-synthesis. The performance and robustness of the controlled vehicle were analyzed experimentally and by computer simulation. The design was tested under actual driving conditions and was found to perform well.

VEHICLE LANE-TRACKING CONTROL WITH STEERING TORQUE INPUT

SUMMARY Alternative methods of automatic steering system are investigated by using a vehicle-mounted camera that detects lane markers ahead of the vehicle. The control input of such a steering system can be classified into steering angle and steering torque. This paper investigates the physical characteristics of automatic lane-tracking controller using steering angle and steering torque as the control input, and compares their differences. Generally, most of researches about lane-tracking control manoeuvre deal with steering angle control method due to its excellent robustness. In contrast, the steering torque control provides some degree of freedom in permitting the driver to steer the vehicle, thus it has potential for development as a steering assist mechanism. In this paper, the controller design is Linear Quadratic (LQ) controller based on the simplified dynamics of a 2 degree-of-freedom bicycle model and simplified steering model.

Automatic path tracking using linear quadratic control theory

The authors conducted a study of automatic path tracking performance in the automated highway system (AHS) public trials that were carried out in Japan in 1996. A comparison was made of proportional-plus-derivative (PD) control and linear quadratic (LQ) control as two potential control systems. Because the PD control system lacked state feedback of yaw motion, the interference of yaw motion on lateral motion could not be eliminated. This made it impossible to achieve both satisfactory response and convergence. The LQ control system, on the other hand, had a larger number of state feedback coefficients, enabling lateral motion to be separated from yaw motion. This made it possible to set the response and convergence of lateral motion at will. Driving on an automated highway system is premised on the receipt of feedforward information from the road-side infrastructure. In this study, it was shown both theoretically and experimentally that road curvature can be estimated logically as a vehicle travels along even in the absence of feedforward information on curvature. Logical estimates are obtained with an algorithm in which curvature is treated as a state variable. It was also shown experimentally that an autonomous lane-tracking vehicle can even navigate road curves of unknown curvature by using a regulator configured around the method of estimating road curvature logically.

Investigation of automatic path tracking using an extended Kalman filter

Abstract This paper proposes a lane marker recognition method that uses the steering angle in addition to image information. A Kalman filter was reconfigured regarding the yaw motion and lateral motion of lane markers, previously treated as a stochastic process, as the states of a vehicle model driven on the basis of the steering angle. Driving tests conducted with an actual vehicle verified that this method provides good tracking at the time of steering input and avoids misrecognition of lane marker candidate points in inclement weather.

Research on automated lane tracking using linear quadratic control : control procedure for a curved path

Research has been done recently on automated steering systems for automobiles which would make hands-free driving possible. In the present research, it was shown both experimentally and by simulations that the use of linear quadratic (LQ) control improves lane tracking control performance. It was observed that LQ control improves tracking performance by working to separate yaw motion from lateral motion. It was found that both satisfactory steady-state characteristics and response could be obtained by suitably weighting lateral motion. The first part of this paper shows how the use of LQ control facilitates lane tracking along a straightway. The second half describes a method for enabling an automated vehicle to navigate curves. It is shown that detection of the vehicles lateral deviation alone, without any feed-forward information about the road curvature or other conditions, is sufficient to secure stable cornering performance. For the covering abstract, see IRRD 490001.

Study on automatic path tracking using virtual point regulator

This study discusses a vehicle path tracking strategy using a virtual point ahead of the vehicle to trace the desired path. Although the vehicle center of gravity can also be employed for the tracking, it is impossible to design the yaw control independently from the controlled lateral motion. By contrast, the yaw motion, as well as the lateral motion, can be controlled to obtain its own desired performance when the virtual point is used for the tracking, although this applies with certain reservations. Additionally, employing the virtual point also secures good robust stability and disturbance suppression performance of the control system.

Investigation of automatic path tracking control using four-wheel steering vehicle

This paper investigates the use of a four-wheel steering system for the control of a vehicle, in the context of automatic path tracking. A four-wheel steering system provides two independent control inputs which can significantly enhance handling and stability. In this paper, the lateral deviation at the front and rear virtual points are proposed to be state variables in the control system design procedure instead of lateral deviation at the center of gravity and yaw deviation in order to decouple lateral and yaw motion during path tracking maneuvers. Simulations of straight and curved path tracking are conducted to investigate the validity of the proposed control system.

Investigation on Estimation of Vehicle Side Slip Angle by Using Extended Kalman Filter

The extended Kalman filter was employed to estimate vehicle side-slip angle accurately even under the condition of low road friction and the large lateral gradient road. The direct integration method is the base structure of this estimator, and the longitudinal equation of motion was included to augment the system , and to configure the Kalman filter. For compensation of estimation value drifted by the sensor signal offset , a nonlinear map between actual yawrate and the yawrate value using in the calculation was proposed. The performance of the extended Kalman filter and the non-linear map was validated in the simulation.

1303 Investigation on the Influence of Side Slip Angle to the Driver's Handling Behavior

This paper describes the drivers steering behavior affected by the vehicle side slip angle during changing lanes. In order to investigate the influence of the sideslip angle to driver’s steering behavior, driving simulator is employed to realize various vehicles with different side slip characteristics. We prepared three specifications, i.e. yaw rate and side-slip angle generate in the same direction, the opposite direction, and side-slip angle is kept to zero. In this study, we used two type second order prediction model. The one is the second order prediction by yaw rate and side-slip angle. Another one is the second order prediction by only yaw rate. And we discussed the effect of side-slip angle on the driver’s forward prediction with compared the two prediction models. 1.序論 車両の位置や向きを制御するために,ドライバは車両挙動をフィードバックして操舵している.車両挙動のフ ィードバック信号の特性,つまり車両の運動特性によって運転の難易度が変化することは広く知られている(安部, 2008).車両の応答性が優れていればドライバの負担は軽減され,そうでなければ増大することが McRuer のクロ スオーバーモデルなどで示されている.(McRuer,1967).経験的には,車両を質点とみなしたときの応答性だけ ではなく,剛体としての「動き方」も運転しやすさに影響すると考えられる. 車両の「動き方」に影響を与える要因として車体横すべり角が挙げられる.(芝端他,1985)では横すべり角が 約 0.01rad以上発生するとドライバにリアの振り出し感が生じ,危険感が増加することが示されている.また,(森 他,2010)では,車体横すべり角が定常的にヨーレイトに対して負の値になると,車線変更時に目標ラインに対し てオーバーシュートしてしまうことが示されている.車体横すべり角に影響されてドライバ自らが余計な操舵を してしまうことも指摘されている.しかし,車体横すべり角がどのような原因で操舵に影響を与えるかは明らか にされていない.本研究では,ヨーレイトの特性を同一にし,車体横すべり角の特性のみを種々に変更してその 原因を調べた.ドライビングシミュレータで高速走行時の車線変更の実験を行い,操舵挙動などの時系列データ 車体横すべり角が操舵に与える影響について 鈴木 雄太,風間 恵介,孕石 泰丈 毛利 宏,菅沢 深 Yuta SUZUKI , Keisuke KAZAMA, Yasutake HARAMIISHI, Hiroshi MOURI and Fukashi SUGASAWA *1,*2 University of Yamanashi,Graduate School of Medical and Engineering Department of Education 4-3-11,Takeda, Kofu-shi, Yamanashi,400-8511 Japan *3 Tamagawa Academy & University, College of Engineering 6-1-1,Tamagawagakuen, Machida-shi, Tokyo,194-0041 Japan Received 30 January 2014

Lane-tracking control performance of four-wheel-steering automobile

Abstract This paper investigates the use of four-wheel-steering system for the control of vehicle, in the context of automatic lane-tracking. In this paper, the lane-tracking control system is designed on the basis of the four-wheel-steering automobile whose desired steering response is realized by the application of model matching control. Using simplified linear 2 degree-of-freedom bicycle model, simulation study and theoretical analysis are conducted to evaluate the lane-tracking control performance of active four-wheel-steering automobiles which have different desired steering response. A comparative study clearly reveals their advantages in lane-tracking performance.