A torque distribution method for a vehicle driven by an in-wheel motor

Abstract

The invention relates to a torque distributing method for in-wheel-motor driven vehicles. Through the distribution of the output torque of in-wheel motors and the output torque of a mechanical brake, the whole-vehicle target control force and the whole-vehicle force moment, which are needed by vehicle handling stability, are realized. The torque distributing method comprises the following steps: step 1, establishing an optimal control distribution equation for longitudinal force of electric wheels according to whole-vehicle needed longitudinal resultant force, whole-vehicle needed lateral resultant force and whole-vehicle needed yawing moment by adopting an optimal control distribution method; step 2, obtaining the optimal longitudinal force of each electric wheel according to the established optimal control distribution equation for the longitudinal force of the electric wheels, and combining the optimal longitudinal force with the relationship between the output torque of the electric wheels and the longitudinal force of the electric wheels so as to obtain the output torque of the electric wheels; and step 3, obtaining the output torque of the in-wheel motors and the output torque of the brake according to the relationship between the output torque of the in-wheel motors and the output torque of the brake.

Description

technical field [0001] The invention belongs to the field of electric vehicles and vehicle dynamics control, and relates to a method for distributing torque between hub motors and brakes, in particular to a method for distributing driving torque and braking torque between hub motors and brakes. Background technique [0002] In-wheel motor-driven vehicles are one of the research hotspots in the field of electric vehicles. The unique structural characteristics and layout of the in-wheel motor drive system have brought technological innovation to the chassis structure of the vehicle, which is conducive to optimizing the vehicle structure design, giving full play to the advantages of electric technology, and tapping the potential of vehicle dynamics control. [0003] In the in-wheel motor drive system, multiple in-wheel motors and brakes constitute a redundant actuator system. It is necessary to reasonably distribute the torque between all in-wheel motors and brakes in order to ...

AI Technical Summary

Problems solved by technology

The rule-based method focuses on the formulation of torque distribution rules, which has a small amount of calculation and a fast solution speed. However, it cannot handle the constraints of in-wheel motors and brakes well. Some of the electric wheels tend to reach the constraint boundary in advance, while others The motorized wheels are underutilized to the extent that overall control is reduced

The main content of the control assignment method based on the optimization function is the determination of the objective function and the solution to the objective function under the constraint conditions. The distribution accuracy is high, but it is difficult to meet the actual constraints in some complex working conditions

In the current methods, most of them only distribute the output torque of the hub motor without considering the torque distribution of the mechanical brake. When the required braking torque is large, the braking torque of the hub motor reaches the saturation limit, while the mechanical The brakes are not working, so there is a certain defect

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