Abstract
This paper describes on-line preview planning for a desired signal of a 3-wheeled vehicle.
We have proposed to combine on-line planning for a desired signal and control system design. In this method, the planner is designed as a part of the control system by traditional design methods for control system design. In off-line planning, the control system reduces the influence of disturbance, parameter perturbation and initial value. In on-line planning, both the planning for the desired signal and the control system can reduce the influence of disturbance etc. That is, on-line method can reduce the influence better than off-line planning by changing the desired signal with the state of the control system.
Control system performance can be improved by utilizing the future desired signal and/or the disturbance signal in advance. Such a control is called “PREVIEW CONTROL”. Preview control can't be utilized for on-line planning because the future desired signal can be varied with the future state of the control system. However, in the proposed “PREVIEW PLANNING” the future information of the restriction of the desired signal is utilized instead. The preview planning can prevent the controlled variables from spilling over the permitted domain better than without preview planning. In on-line planning a feedback loop is constructed and in preview planning feedforward is added to it. In the motion of 3-wheeled vehicles, the domain within which the vehicle can move is usually restricted by various obstacles etc. Where the information of the obstacles within a certain distance can be given by the sensor, on-line planner can utilize the future information of the restriction in advance. The vehicle can start to avoid the obstacles earlier than without preview planning. We show the simulation results in order to clarify its effectiveness.
