Unpiloted independently-driven and steered vehicle dynamics control quantity obtaining method

Abstract

The invention relates to an unpiloted independently-driven and steered vehicle dynamics control quantity obtaining method. The method comprises the steps of: computing a vehicle dynamics control quantity achievable region on the basis of obtaining the information of a vehicle-road tracking system; adjusting the tracking expect deviation of the system according to the region; judging and processing the feasibility of the finally obtained vehicle dynamics control quantity; and timely evaluating and using the disturbance information of the system to improve the effectiveness, the reasonableness and the robustness of the vehicle dynamics control quantity obtained in a computation way. Therefore, the unpiloted AWID (applied wireless identifications)-AWIS (alexa web information service) vehicle can track a road path with greater curvature on a low-attachment coefficient road surface and a separation road surface at better precision and a higher speed, so that the vehicle is ideal in dynamics control effect and safe to run.

Description

technical field [0001] The invention belongs to the technical field of vehicle dynamics; in particular, it relates to a method for obtaining vehicle dynamics control quantities of an unmanned all-wheel independent drive-independent steering (All Wheel Independent Drive & Steering, referred to as AWID-AWIS) vehicle. Background technique [0002] All-wheel independent drive-independent steering (AWID-AWIS) vehicle is a new type of vehicle developed in the international automotive industry in recent years. It cancels the axle connecting the left and right wheels in traditional vehicles, breaks through the constraints of the traditional drive-steering mechanism, With a novel wheel-independent drive-brake-steer mechanism, the vehicle has obtained drive redundancy (the vehicle only has three degrees of freedom, longitudinal, lateral and yaw, but each wheel can generate longitudinal and lateral Two control forces; assuming that the vehicle has m independent wheels in total, 2m cont...

AI Technical Summary

Problems solved by technology

Chinese patent application "Acquisition Method of Vehicle Dynamics Control Quantity of Independent Drive-Independent Steering Vehicle" (Application No.: 201010559872.3) describes a method for obtaining the vehicle dynamics control quantity of a manned independent drive-independent steering vehicle. It is used for dynamic tracking control of the driver's steering wheel angle, accelerator pedal opening angle, and brake pedal opening angle commands; while on an unmanned AWID-AWIS vehicle, the total vehicle dynamics control is used to control the road tracking, the method provided by this patent cannot meet this requirement

[0006] 2) with {v xd , Δy d , Δψ d } (where Δy d = 0, Δψ d =0) is the expected value of vehicle dynamics control target (v xd , Δy d , Δψ d Respectively referred to as expected vehicle speed, expected distance deviation, expected yaw angle deviation), and calculate the v obtained in step 1) x , Δy, Δψ between the system tracking expectation deviation e vxd =v xd -v x 、e Δy =Δy d -Δy, e Δψ =Δψ d -Δψ, as the input of the vehicle dynamics controller, using the vehicle dynamics model and PID, sliding mode control, fuzzy control, H ∞ Robust control, optimal control and other methods are used to calculate the vehicle dynamics control quantity U=[F x f y m z ] T , that is, the total longitudinal force control F x , Total lateral force control F y , total yaw moment control amount M z , but the calculation of U does not consider the constraints of the reachable domain of the vehicle dynamics control quantity

[0011] (3) The real-time observation and utilization of system disturbances are not considered, which will lead to the generation of vehicle dynamics control quantities that are too conservative to consider the robustness of system control, and may also exceed the constraints of the underlying wheel control force and cannot be effectively implemented , and the resulting additional perturbation

In particular, when system disturbances and additional disturbances exceed the actual control capabilities of the underlying wheels, the system control will be unstable

[0012] The above deficiencies make unmanned AWID-AWIS vehicles drive on low adhesion coefficient roads and separated roads, especially when driving at high speeds, the dynamic control effect is not ideal, and sometimes even cause serious problems such as instability and loss of control of the vehicle

Images