Toyota makes hybrids smoother
Prius+ is the first series production application but system could be used on other hybrids
AE in Technology.
- Published in Technology.
Easy rider: Varying motor torque mitigates pitching motion
The Toyota Prius+ seven seat MPV uses the hybrid powertrain to improve ride comfort.
The so-called pitch and bounce control function uses torque from the electric motor to counteract the vehicle's tendency to pitch under hard braking and acceleration.
Chief engineer Makoto Okabe said: “The system improves ride comfort because pitching is reduced. But we also found that it improves handling because the load on the tyre contact patch is more constant.”
By varying output of the 207Nm permanent magnet motor by no more than a few per cent, the powertrain's output can help to mitigate the tenancy of the vehicle's nose to dive under braking or rise under acceleration; under these conditions output is increased or decreased respectively.
The system is triggered by data from the wheel speed sensors: as the vehicles accelerates and decelerates, the tyres' effective diameter changes, and the change in angular velocity is used by the system controller to modify motor torque.
The technology was first developed by Toyota's advanced engineering team. The Prius+ is the first series production application but Okabe said that the system could be used on other Toyota and Lexus hybrid vehicles.
