Brake Actuator Motor Temperature Estimation Without a Sensor
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Solution Overview
Problem
Existing vehicle brake systems with electromechanical actuators face challenges in maintaining precise braking performance, especially in the absence of a temperature sensor, as motor temperature significantly affects braking force.
Innovation Solution
A method and device for controlling the electromechanical brake actuator by estimating the motor temperature using corrective coefficients based on the ratio of angular speed to supply current and ohmic resistance, allowing for precise control of braking force without a temperature sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a temperature sensor is installed to measure motor temperature for precise braking control, then braking precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces the physical temperature sensor (mechanical/thermal measurement system) with an electrical measurement system that determines temperature indirectly through motor constant and ohmic resistance measurements. The control device calculates temperature based on electrical parameters (motor constant K, ohmic resistance R) rather than direct thermal sensing, thereby eliminating the need for additional temperature sensors while maintaining temperature awareness for braking control.
Solution Approach 2:
The patent introduces electrical parameters (motor constant and ohmic resistance) as intermediary variables that mediate between the motor's actual temperature and the control system. Instead of directly measuring temperature, the system measures these electrical intermediaries which change with temperature, allowing temperature inference without direct thermal contact or additional sensors.
2Reliability
If a temperature sensor is installed to monitor motor temperature, then braking performance is improved, but mass and cost of the actuator increase
Solution Approach 1:
The patent eliminates the need for physical temperature sensors by substituting them with electrical measurement capabilities that already exist in the motor control system. By using motor constant and ohmic resistance measurements instead of thermal sensors, the system reduces component mass while maintaining the ability to compensate for temperature effects on braking performance.
Solution Approach 2:
The motor's existing electrical characteristics (motor constant and ohmic resistance) serve dual purposes: they are necessary for motor operation control and simultaneously provide temperature information. This self-service approach means the motor effectively measures its own temperature through its operational parameters without requiring external sensing infrastructure, reducing overall system mass.
3Measurement precision
If direct temperature measurement is used, then temperature accuracy is improved, but device complexity and power consumption increase
Solution Approach 1:
The patent replaces direct thermal measurement (which would require active temperature sensors consuming power) with electrical parameter measurements. The motor constant and ohmic resistance can be determined from existing voltage and current measurements during normal motor operation, avoiding the need for additional power-hungry temperature sensing circuitry while maintaining temperature measurement capability.
Solution Approach 2:
The patent makes the existing electrical measurement system multi-functional: the same voltage and current measurements used for motor control also provide temperature information through motor constant and ohmic resistance calculations. This universal approach eliminates the need for separate temperature measurement power circuits, reducing overall power consumption while achieving temperature monitoring.
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 enables more efficient and precise control of braking force, reducing the mass, power, and cost of the electromechanical brake actuator while maintaining effective braking performance.
Implementation Method 1
the temperature of the motor being estimated from the motor constant and the ohmic resistance of the motor
Implementation Method 2
the temperature of the motor being estimated from the motor constant and the ohmic resistance of the motor
Implementation Method 3
The electromechanical actuator comprises an electric motor
Data Source
AI summary
A vehicle wheel control device is configured to determine a first corrective coefficient of temperature of the motor from a ratio of an angular speed of the motor to the supply intensity of the motor depending on the supply voltage of the motor. The control device is configured to determine a second corrective coefficient of temperature of the motor from a ratio of the ohmic resistance of the motor to the constant of the motor depending on the temperature of the motor.