Electronic parking brake with feedback control and cable strain gage

摘要

A parking brake system for a vehicle with a brake device for braking the vehicle, at least one cable actuating the brake device, and a motor actuating the cable. A strain gage is connected to the cable, the strain gage having an output, the strain gage output being a function of a strain in the cable. A controller receives an input from the strain gage output, the controller controlling the motor as a function of the strain gage output. In addition, a strain gage for an actuation cable in a vehicle includes a coil surrounding the cable, the coil having a diameter varying as a function of a force on the cable, and a circuit. The circuit includes a voltage supply for providing a voltage across the coil and a detector for measuring electrical changes in the circuit as a function of the diameter of the coil.