Roll vibration damping control system for vehicle and target roll moment computing method therefor

Abstract

A roll vibration damping control system includes an electronic control unit configured to: compute a sum of a product of a roll moment of inertia and a roll angular acceleration of a vehicle body, a product of a roll damping coefficient and a first-order integral of the roll angular acceleration, and a product of an equivalent roll stiffness of the vehicle and a second-order integral of the roll angular acceleration, as a controlled roll moment to be applied to the vehicle body; compute a roll moment around a center of gravity of a sprung mass as a correction roll moment, the roll moment being generated by lateral force on wheels due to roll motion; and compute a target roll moment based on a value obtained by correcting the controlled roll moment with the correction roll moment.

What is claimed is: 
     
         1 . A roll vibration damping control system for a vehicle, the roll vibration damping control system comprising:
 a roll angular acceleration detector configured to detect a roll angular acceleration of a vehicle body;   an actuator configured to generate a roll moment to be applied to the vehicle body; and   an electronic control unit configured to:
 store a roll moment of inertia, a roll damping coefficient, and an equivalent roll stiffness of the vehicle, 
 compute a sum of a product of the roll moment of inertia and the roll angular acceleration detected by the roll angular acceleration detector, a product of the roll damping coefficient and a first-order integral of the roll angular acceleration, and a product of the equivalent roll stiffness and a second-order integral of the roll angular acceleration, as a controlled roll moment to be applied to the vehicle body, 
 compute a roll moment around a center of gravity of a sprung mass as a correction roll moment, the roll moment being generated by lateral force on wheels due to roll motion, 
 compute a target roll moment based on a value obtained by correcting the controlled roll moment with the correction roll moment, and 
 control the actuator such that the roll moment that the actuator generates becomes the target roll moment. 
   
     
     
         2 . The roll vibration damping control system according to  claim 1 , wherein the electronic control unit is configured to compute the correction roll moment based on a vehicle speed and the roll angular acceleration. 
     
     
         3 . The roll vibration damping control system according to  claim 1 , wherein the electronic control unit is configured to apply the same high-pass filter to the roll angular acceleration, the first-order integral, the second-order integral, and the correction roll moment the same number of times at least twice. 
     
     
         4 . The roll vibration damping control system according to  claim 1 , wherein the electronic control unit is configured to apply the same low-pass filter to the roll angular acceleration, the first-order integral, the second-order integral, and the correction roll moment. 
     
     
         5 . The roll vibration damping control system according to  claim 1 , wherein the actuator includes active suspensions provided in association with the wheels. 
     
     
         6 . The roll vibration damping control system according to  claim 1 , wherein the actuator includes an active stabilizer provided in association with at least front wheels of the wheels or rear wheels of the wheels. 
     
     
         7 . The roll vibration damping control system according to  claim 1 , wherein the actuator includes in-wheel motors respectively assembled to the wheels. 
     
     
         8 . The roll vibration damping control system according to  claim 1 , wherein the actuator includes an active steering system provided in association with at least front wheels of the wheels or rear wheels of the wheels. 
     
     
         9 . A target roll moment computing method for a roll vibration damping control system for a vehicle, the roll vibration damping control system including
 a roll angular acceleration detector configured to detect a roll angular acceleration of a vehicle body,   an actuator configured to generate a roll moment to be applied to the vehicle body, and   an electronic control unit configured to control the actuator such that the roll moment becomes a target roll moment, the target roll moment computing method comprising:   storing, by the electronic control unit, a roll moment of inertia, a roll damping coefficient, and an equivalent roll stiffness of the vehicle;   computing, by the electronic control unit, a sum of a product of the roll moment of inertia and the roll angular acceleration detected by the roll angular acceleration detector, a product of the roll damping coefficient and a first-order integral of the roll angular acceleration, and a product of the equivalent roll stiffness and a second-order integral of the roll angular acceleration, as a controlled roll moment to be applied to the vehicle body;   computing, by the electronic control unit, a roll moment around a center of gravity of a sprung mass as a correction roll moment, the roll moment being generated by lateral force on wheels due to roll motion; and   computing, by the electronic control unit, the target roll moment based on a value obtained by correcting the controlled roll moment with the correction roll moment.   
     
     
         10 . The target roll moment computing method according to  claim 9 , wherein the correction roll moment is computed by the electronic control unit based on a vehicle speed and the roll angular acceleration. 
     
     
         11 . The target roll moment computing method according to  claim 9 , wherein the same high-pass filter is applied by the electronic control unit to the roll angular acceleration, the first-order integral, the second-order integral, and the correction roll moment the same number of times at least twice. 
     
     
         12 . The target roll moment computing method according to  claim 9 , wherein the same low-pass filter is applied by the electronic control unit to the roll angular acceleration, the first-order integral, the second-order integral, and the correction roll moment.