Design and Control of Electric Drivetrains for Road Vehicles
DBT: Two-Speed Transmission for EVsOur team invented a patent-pending, high-efficiency, seamless two-speed-ratio dual-brake transmission for electric drivetrains dubbed the DBT. The DBT is always engaged and does not require a clutch for gear shifting as it uses synchronized control of the traction motor's speed and the brake torques to achieve seamless gearshifts. The DBT is composed of two planetary gear sets rigidly linked at the ring gears and the sun gears with brakes on the common sun and common ring. Braking the common ring channels the traction torque through the sun (for the first speed ratio) and vice-versa, just like a differential channels the traction torque to the wheel experiencing the least resisting torque. Please contact Prof. Boulet to discuss licensing opportunities. Videos of the DBT can be found here:
http://samanrahimi.weebly.com/projects.html |
Control of Synchromesh Friction in a Clutchless AMT for EVsAutomated manual transmission (AMT) is also a good choice for electric vehicles as it is efficient, but the challenge is not to add an external clutch and instead use only the cone clutch of the synchronizer for gear shifting while controlling the torque of the traction motor. We designed a control system that keeps the cone clutch at the boundary of the mixed lubrication regime to maximize torque transfer and minimize speed synchronization time while reducing wear of the cone clutch to extend its life.
|
Robust Force Control of Solenoids for EV TransmissionsIn an EV, it doesn't make much sense to have a hydraulic or pneumatic system to power an actuator, such as a synchronizer actuator for changing gears in an automated manual transmission. Instead, we set out to study the use of solenoids as force actuators for gear shifting. We can control the force up to hundreds of Newtons on very compact solenoids, which we demonstrated on the DBT and the synchromesh friction test bed.
|