Sliding Door Motor Angle Detection Without Hall Sensors
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Solution Overview
Problem
Existing sliding door control devices require three Hall ICs to detect the rotation angle of the motor, which increases manufacturing costs and makes the system vulnerable to failure if any of the Hall ICs fail.
Innovation Solution
A sliding door driving device that uses a shunt resistor to detect the rotation angle of the motor, eliminating the need for position sensors and improving resistance to failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If three Hall ICs are installed to detect the rotation angle of the motor, then the rotation angle detection is achieved, but the manufacturing cost increases
Solution Approach 1:
The patent extracts the rotation angle detection function from the Hall IC position sensors and implements it through electrical current measurement using a shunt resistor. By measuring the current consumed by the motor phases and calculating the rotation angle based on current ratios, the system eliminates the need for separate position sensing components, thereby reducing manufacturing cost while maintaining detection capability
Solution Approach 2:
The shunt resistor serves multiple functions: it is used for current measurement for motor control and simultaneously provides rotation angle detection information. This multi-functionality eliminates the need for dedicated position sensors, reducing component count and manufacturing cost while achieving both current control and position detection
2Measurement precision
If three Hall ICs are installed to detect the rotation angle of the motor, then the rotation angle detection is achieved, but the system reliability decreases when one Hall IC fails
Solution Approach 1:
By removing the Hall IC position sensors and implementing rotation angle detection through electrical current measurement, the patent eliminates the single point of failure associated with individual Hall ICs. The shunt resistor-based measurement method provides inherent redundancy as it measures overall system current rather than relying on individual sensor outputs
Solution Approach 2:
The patent implements continuous feedback measurement of motor phase currents through the shunt resistor, allowing the control system to monitor motor operation and calculate rotation angle in real-time. This feedback mechanism provides ongoing verification of motor position without the vulnerability of static position sensors, enhancing system reliability through active monitoring
3Measurement precision
If position sensors are installed in the sliding door driving device, then the rotation angle of the motor can be obtained, but the device complexity increases
Solution Approach 1:
The patent merges the position detection function with the existing current measurement circuitry by using the shunt resistor for both motor control current measurement and rotation angle detection. This consolidation eliminates separate position sensing subsystems, reducing device complexity while maintaining the capability to obtain rotation angle information
Solution Approach 2:
The shunt resistor and current measurement system serve dual purposes: controlling motor operation through current regulation and detecting rotation angle through current ratio analysis. This multi-functional approach eliminates the need for dedicated position sensors, simplifying the overall device architecture
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
The use of a shunt resistor allows for reliable detection of the motor's rotation angle without the need for additional position sensors, reducing manufacturing costs and enhancing system reliability.
Implementation Method 1
a shunt resistor disposed between the power source and the power conversion device, and wherein the control device obtains a rotation angle of the motor based on an output of the shunt resistor
Data Source
AI summary
A sliding door driving device includes: a power source; a motor that outputs power to open and close the door, a motor driving circuit that connects the power source and the motor to each other; and a motor control device that controls the motor driving circuit. The motor control device includes an inverter that converts DC power supplied from the power source into AC power, and a shunt resistor disposed between the power source and the inverter. The position detection unit of the motor control device obtains the rotation angle of the motor based on the output of the shunt resistor.