GRD Journals- Global Research and Development Journal for Engineering | Volume 2 | Issue 8 | July 2017 ISSN: 2455-5703
Inverse Vehicle Dynamic Model of a Two Wheeler with Power Steering: A Graphical Approach Desh Deepak Gautam M. Tech Student Department of Mechanical Engineering Goel Institute of Technology & Management, Lucknow, India
Abstract As the traffic is increasing day by day the chances of accidents are increased. These accidents are mostly happen due to human errors. Development of inverse dynamic controller necessary as it can replace the driver and track the predefined path. A bond graph model of a two wheeler vehicle is developed and in this model manual and electrical power steering systems are attached and a comparison of both systems for evaluating the response is done. An inverse vehicle dynamics model is developed. This inverse model gives a torque to this model to follow a predefined path. An expression is derived to compute the steering angle in terms of longitudinal velocity and vehicle projectile rate for a predefine path. The inverse vehicle dynamics model is connected by an overwhelming controller in such a way that the output of forward model is feedback to inverse two wheeler model. The vehicle’s position is compared with the desired trajectory and the error signal is given to the inverse two wheeler model to produce the desired output. Keywords- Two Wheeler Model, Bond Graph Modeling, Electrical Power Steering, Ghost Controller, Inverse Two Wheeler Model, Manual Steering, Overwhelming Controller
I. INTRODUCTION Day by day numbers of vehicles on road are increasing by which roads are becoming congested and risky. 1.4 million People were perished on the world’s roads in 2017[1] and this is intolerably high. Some changes in the transportation control system are required. Most of the road accidents happen due to human errors. In mostly developed countries, transport infrastructure has been improved. The advanced freeways are ten times securer than regular roads but it is not economically favorable to establish new roads with intelligent traffic control systems. One of the options to encounter this problem is the entry of intelligent autonomous vehicle. An autonomous vehicle is described as the vehicle which can move on its own or the one which is self-driven. An intelligent vehicle is able to reduce 90% of road accidents that are caused by human error and can save human life. A. Inverse Vehicle Dynamics Inverse vehicle dynamics is combination of inverse model of vehicle along with actual vehicle. Forward and inverse dynamic problem were first developed by Newton. The forward problem is to determine the kinematic parameters (position, velocity, acceleration) of body subjected to given set of forces. The inverse problem is to determine forces that should be applied to body to maintain the required kinematics parameters of the body in motion.
Fig. 1: Forward vehicle model
As shown in Fig. 1, input to the actual vehicle is steering angle and torque and the output is its centroid-position x, y,. In the inverse model as shown in Fig. 2, the position is given as input; required torque and steering angle are determined using control law.
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