Hub direct-drive air suspension system based on NMPC and cooperative control method

Abstract

The invention discloses an NMPC-based hub direct-drive air suspension system and a cooperative control method, and the suspension system consists of a sensor module, an expansion observer module, an NMPC controller, a damping coefficient controller, a damping coefficient execution mechanism, an additional air chamber controller and an additional air chamber execution mechanism. The input of the NMPC controller is the vertical displacement and speed of the sprung mass, the vertical displacement and speed of the mass of the tire and the motor rotor, and the vertical displacement and speed of the mass of the motor stator and the residual unsprung mass, and the output of the NMPC controller is the optimal suspension force. The optimal suspension force of the system is solved by taking the optimal performance of the suspension system, reducing the eccentric distance of a motor and prolonging the service life of the motor as control targets, the optimal suspension force is distributed through a damping coefficient and an additional air chamber execution mechanism in sequence, and cooperative control over the damping coefficient of the air suspension and an additional air chamber is achieved. The vehicle body acceleration, the suspension stroke, the tire deformation and the motor eccentric distance are further reduced, and the comprehensive performance of the hub direct-drive air suspension system is improved.

Description

technical field [0001] The invention belongs to a semi-active suspension installed on an electric vehicle, in particular to a hub direct-drive air suspension system and the coordinated control of the damping coefficient and an additional air chamber of the hub direct-drive air suspension system. Background technique [0002] Electric vehicles driven by in-wheel motors are a representative type of new energy vehicles. Hub motor drive is to install the motor directly on the wheel and drive the car to move. Its advantage is that the direct drive of the hub motor saves some transmission devices such as gearbox and reducer; because the driving torque is independently controllable, the torque speed is easy to measure , so it has significant advantages in terms of stability, active safety control and energy saving. However, on the one hand, the introduction of the in-wheel motor increases the unsprung mass, which causes the deterioration of the ground contact and ride comfort of t...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the problem of poor control performance caused by severe parameter coupling, hysteresis of dynamic characteristics and increased constraints in the existing hub direct drive air suspension system, and propose a hub based on nonlinear model predictive control (NMPC) Direct drive air suspension system and cooperative control method

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