Modifications
Toyota Motor Corp.
To improve stability, controllability and ride comfort, TOYOTA has developed as integrated chassis control system consisting of Active Four Wheel Steering (A-4WS), Active Hydropneumatic Suspension (A-SUS), ABS and TRC. The system, which is available on the current ’91 model SOARER sold on the domestic market, realises a significant advance in total vehicle dynamics - due partly to the superior characteristics of the new A-4WS and A-SUS and partly to the enhancement accruing from integration - and makes an important contribution to active safety.
SUMMARY AND CONCLUSION
A chassis control system integrating A-4WS, A-SUS. ABS and TRC has been developed.
The A-4WS system features yaw velocity feedback control. which is confirmed to be very effective in improving not only steering response but also stability against external disturbances, and at low speeds makes use of mechanical rear steering to reduce the turning radius.
The A-SUS system utilises hydropneumatic cylinders in place of conventional springs so that vertical load control maybe applied to improve vehicle controllability even in the non-linear range of cornering force.
The integrated chassis control system functions to promote the performance of the individual controls with the result that ride quality, stability and controllability, are raised to new levels and active safety is greatly enhanced.
It is thought that with this advance, automobile electric technology is entering the phase predicted by J.G Riverd where systems will be unified and common use will be made of sensors and ECU:
In this stage of ever-increasing complexity, very careful attention must be paid to the configuration to limit the physical size and to ensure fail-safe operation.
