Showing 3 results for Nonlinear Model
M. A. Saeedi, R. Kazemi, M. Rafat, A. H. Pasdar,
Volume 2, Issue 2 (4-2012)
Abstract
In this paper, a complete model of an electro hydraulic driven dry clutch along with its
performance evaluation has elucidated. Through precision modeling, a complete nonlinear
physical and full order sketch of clutch has drawn. Ultimate nonlinearities existent in the
system prohibits it from being controlled by conventional linear control algorithms and to
compensate the behavior of the system mainly during gearshift procedure, a nonlinear control
program has been developed and tested. A unique approach to estimating clamp force has been
adopted which makes the system comparable to a real world and full-physical one. Based on
this type of modeling, the control approach is a true and feasible, ready-to-implement program
which is based only on reality. The clutch model has been validated against experiments and
great agreement has been attained since, every fine point has been taken into account and
nothing is out of representation unless it is not crucial to system performance. The nonlinear
control program does the control task very well and administrates the system in the desired
trajectory.
Ehsan Alimohammadi, Esmaeel Khanmirza, Mr Hamed Darvish Gohari,
Volume 8, Issue 4 (12-2018)
Abstract
In cruise control systems, the performance of the controller is important. Hence, in order to have accurate results, the nonlinear behavior of a vehicle model should also be considered. In this article, a vehicle with a nonlinear model is controlled by using a nonlinear method. The nonlinear term of the model is the generated torque of engine, which is a polynomial equation. In addition, feedback linearization is used as a nonlinear method in order to design two parallel controllers to control the movement of the vehicle. These two parallel controllers are used to control braking and gas pedals which are in charge of the angular velocity of the wheels. To check the performances of controllers, first, each controller is used separately. Finally, two parallel controllers are used to track the reference signal. Comparison between results shows that the designed controller is able to reduce the convergence time of about 10 seconds. This improvement is near 35% in comparison with near studies. In addition, it can reduce the error between the velocity of the vehicle and the values of the reference signal that results in more safety for passengers.
Mr Seyed Amir Mohammad Managheb, Mr Hamid Rahmanei, Dr Ali Ghaffari,
Volume 14, Issue 1 (3-2024)
Abstract
The turn-around task is one of the challenging maneuvers in automated driving which requires intricate decision making, planning and control, concomitantly. During automatic turn-around maneuver, the path curvature is too large which makes the constraints of the system severely restrain the path tracking performance. This paper highlights the path planning and control design for single and multi-point turn of autonomous vehicles. The preliminaries of the turn-around task including environment, vehicle modeling, and equipment are described. Then, a predictive approach is proposed for planning and control of the vehicle. In this approach, by taking the observation of the road and vehicle conditions into account and considering the actuator constraints in cost function, a decision is made regarding the minimum number of steering to execute turn-around. The constraints are imposed on the speed, steering angle, and their rates. Moreover, the collision avoidance with road boundaries is developed based on the GJK algorithm. According to the simulation results, the proposed system adopts the minimum number of appropriate steering commands while incorporating the constraints of the actuators and avoiding collisions. The findings demonstrate the good performance of the proposed approach in both path design and tracking for single- and multi-point turns.
