The Clamping Force Control Strategy Research For Electro-Mechanical Braking System

Electro-Mechanical Braking System (EMB) is a new kind of braking system whichuses electric motor to drive actuator generates braking force. Because it has the advantageof compactly structure, high efficiency, environmentally friendly, well brakingperformance and well working with EBD, ABS electronic control system for coordinatedbraking, so it will eventually replace the conventional braking system eventually.In traditional control structure, EMB needs to install the clamping force sensor, butthe sensor is relatively expensive and its installation is not convenient. For this reason, acontrol strategy of non-clamping force sensor based on the parallel Fuzzy and PID forElectro-Mechanical Braking System is proposed in this paper. During braking, thecontroller adjusts the torque of the motor according to the deviation of actual wheel slipratio and target slip ratio, so that keep the actual slip ratio around the target slip ratio. Thenew control strategy is validated by1/4and1/2vehicle braking model in two typical roadconditions. Simulation results show that the system response speed is fast, overshoot issmall and steady-state error is also small, which means the control results are ideal. In theEBD working area，slip ratio-adhesion coefficient curve is increasing monotonically, sothe slip ratio and adhesion coefficient is one-to-one mapping and the main controller couldset rear wheel target slip ratio in accordance with the front wheel actual slip ratio withreference to I-curve. The braking force distribution strategy is validated by1/2vehiclebraking model in two typical road conditions. Simulation results show that β-curve isalways below I-curve and closer to I-curve, this means the front and rear wheels brakingforces meet the distribution requirements.So the proposed control strategy achieved the desired braking effects. Compared withtraditional control strategy, this strategy eliminates the clamping force sensor anddecreases the cost of the sensor installation at the same time. These will lay a goodfoundation for future research.