Automatic regenerative braking system to increase energy efficiency

A system to facilitate regenerative braking of a vehicle, the system comprising:

• an electric machine;
• a gearbox coupled between the electric machine and a wheel of the vehicle, the gearbox being controllable to adjust a gear ratio between the electric machine and the wheel;
• a distance sensor coupled to a portion of the vehicle, the distance sensor configured to provide distance information indicative of a distance to a stop location for the vehicle;
• a torque sensor configured to provide torque information indicative of a torque between the electric machine and the wheel;
• a speed sensor configured to provide speed information indicative of a speed of the electric machine or a speed of the vehicle;
• and
• a controller comprising a processor and a memory storing instructions thereon that, when executed by the processor, cause the processor to:
• send a query to a stored map that includes energy efficiency information corresponding to the vehicle, the query including the distance information and the speed information;
• output a desired braking torque from the map based on the query and a maximum possible energy efficiency value of the stored map;
• control operation of the electric machine or the gearbox based on the torque information and the desired braking torque.

A method of regenerative braking, the method comprising:

• providing an electric machine coupled to a wheel of a vehicle;
• providing distance information, via a distance sensor coupled to a portion of the vehicle, indicative of a distance to a stop location for the vehicle;
• providing torque information, via a torque sensor, indicative of a torque between the electric machine and the wheel;
• providing speed information, via a speed sensor, indicative of a speed of the electric machine or a speed of the vehicle;
• sending a query, via a processor of a controller that includes a memory, to a stored map that includes energy efficiency information corresponding to the vehicle, the query including the distance information and the speed information;
• outputting a desired braking torque from the map based on the query and a maximum possible energy efficiency value of the stored map;
• and
• controlling operation of the electric machine based on the torque information and the desired braking torque.