Control of the Active Suspension for In-Wheel Motor

Abstract

This study raises a new electric wheel with active control of suspension for in-wheel motor. Proceeding from the reality, we made a simulation analysis on these four models: a sample car with no motor, a motor with fixed joint, and active/inactive control suspension for in-wheel motor. During the analysis, less-than-10mm relative vertical displacement was used as a prerequisite, reducing the car's acceleration, the suspension flexivety, and the wheel's load as basic conditions, reducing the wheel's vertical acceleration as the primary target, LQR control of active suspension as the motive. According to the analysis, by optimizing the parameter of inactive control suspension for in-wheel motor, we can solve the vertical problems caused by the electric wheel's mass, but the vertical impact to in-wheel motor is still heavy. However, using active control suspension for in-wheel motor can not only rise the smoothness and safety of the car, but also reduce 64% of the vertical impact comparing to inactive control suspension. This improves the active control suspension for in-wheel motor can effectively resolve the electric cars' vertical problems both theoretically and practically.

Vertical vibration control of an in‐wheel motor‐driven electric vehicle using an in‐wheel active vibration system

“…To reduce the adverse effects of vertical vibration caused by road irregularity, a linear motor is chosen as an active control force generator for installation between the wheel and the IWM to ensure the IWMs and the electric vehicle are always in an optimum vibration state .…”

“…Hence, improvement of the IW vibration system is still in progress, and expectations are high for designing an IW active vibration system to achieve a better working effect. A new kind of active vibration system has been proposed in which the Linear Quadratic Gaussian (LQG) is applied to design the active force controller and experience methods are used to select weighted coefficients of performance indexes . It is believed that LQG control is not sufficiently robust to deal with system parameter variations .…”

Effect of in-wheel motor suspension system on electric vehicle ride comfort

“…Liu M. et al proposed the ride comfort optimization of In-Wheel-Motor EV with In-Wheel vibration absorbers using two control methods such as the linear quadratic regulator (LQR) algorithm for suspension damper and the fuzzy PID method for in-wheel damper [6]. Ma Y. et al proposed a new electric wheel with active control of suspension using LQG control theory for in-wheel motor [7]. Di Tan et al proposed a dual-loop proportion integration differentiation controller based on the particle swarm algorithm is designed to control the active suspension of the EV driven by in-wheel motor [8].…”

“…The EV dynamic models are applied to study vehicle suspension and in-wheel electric motor suspension such as the quarter EV dynamic model [1,7,9], the half EV dynamic model [10] and the full vehicle [2,3]. Vibration sources are considered excitation inputs for the EV dynamic models such as road surface [2,3], in-wheel electric motor as well as the association of both excitation sources [9].…”

Optimization design of semi-active controller for in-wheel motors suspension

“…In addition, the application of in-wheel motors provides opportunities to improve the dynamic control performance when combined with a four-wheel drive, antilock brake system, etc. Nevertheless, the increase of unsprung mass deteriorates riding comfort and handling stability [4,5]. Especially, the tire dynamic load will increase at a high speed.…”