Electric Brake Motor Control for Accurate Pad Contact Detection
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Solution Overview
Problem
The existing technology for detecting the contact position of a pad in an electric disc brake using coils of two systems for one rotor suffers from low detection accuracy due to a small position change amount, which affects the reliability of the position detection process.
Innovation Solution
A control device and method for an electric brake that includes a control unit to output specific current commands to the coils of an electric motor, generating additional torque in one direction and compensatory torque in the reverse direction, enhancing the current change amount and thus improving detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If torque is generated by energizing coils of two systems for one rotor, then the motor can be controlled with redundant systems, but the position change amount becomes small which causes low detection accuracy
Solution Approach 1:
The patent divides the torque generation function into two separate coil systems (first-system coil and second-system coil), each controlled independently. By segmenting the control into separate systems with separate current sensors, the patent enables independent measurement of current in each system, thereby recovering the position detection accuracy that would otherwise be lost due to the small position change amount when both systems operate together.
2Device complexity
If position change amount is measured from only one system, then the system complexity is reduced, but the detection accuracy becomes low
Solution Approach 1:
The patent combines the current measurements from both the first-system coil and second-system coil to determine the position change amount. By merging the information from both systems rather than relying on only one, the patent achieves higher detection accuracy while maintaining a manageable system complexity through unified control logic that processes both current signals.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively increases the detection accuracy of the contact position by amplifying the current change relative to the thrust, reducing the current error and improving the reliability of the position detection process.
Implementation Method 1
an electric motor configured to drive the electric mechanism, the electric motor including coils of two systems
Data Source
AI summary
A motor control device includes a first control unit and/or a second control unit serving as a control unit. The control unit outputs, to a first motor drive unit, a first current command for energizing a first winding set so that first torque, which is torque greater than torque generated in a brake motor by a torque command for generating requested torque requested of the brake motor, and which is in the same direction as a direction of the requested torque, is generated. The control unit also outputs, to a second motor drive unit, a second current command for energizing a second winding set so that second torque, which is torque based on a difference between the requested torque and the first torque, and which is in a direction reverse to the direction of the first torque, is generated.