SPAD Rotor Position Detection in Electric Vehicle Actuators
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric actuator systems for vehicles are heavy, costly, and require complex assembly and energy-intensive, with a need for improved safety, weight reduction, and cost management, especially in fully electric vehicles where energy efficiency is critical.
Innovation Solution
An electric actuator apparatus with a position detection system that integrates a seamless encoded surface on the rotor and a SPAD/CMOS chip or miniaturized camera sensor for high-speed position detection, eliminating the need for separate angular position transducers and dedicated circuitry, allowing for simplified assembly and reduced weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional angular position transducers (encoders or resolvers) are used, then position detection accuracy is improved, but device complexity and weight increase
Solution Approach 1:
The patent merges the position detection function directly into the motor controller by integrating an optical sensor and coded surface into the motor assembly, eliminating the need for separate angular position transducers like encoders or resolvers. This integration reduces device complexity while maintaining position detection accuracy through the use of a reading portion on the rotor and corresponding optical sensor on the stator.
Solution Approach 2:
The patent extracts the position detection functionality from traditional complex transducers and implements it using a simplified optical sensing system. By removing the need for dedicated angular position transducers and their associated copper circuits, the invention achieves accurate position detection with reduced complexity and weight.
2Measurement precision
If traditional angular position transducers are used, then position detection capability is improved, but weight increases
Solution Approach 1:
The patent combines the position detection system with the motor structure itself, using the rotor and stator as integral components of the detection system. This eliminates the need for separate heavy transducer assemblies, reducing overall actuator weight while maintaining position detection capability.
Solution Approach 2:
The patent replaces traditional mechanical/electromechanical position transducers (encoders, resolvers) with an optical sensing system. This substitution eliminates heavy copper circuits and complex mechanical components, significantly reducing weight while providing accurate position detection through optical means.
3Measurement precision
If traditional electromechanical transducers are used, then position measurement is achieved, but energy consumption increases
Solution Approach 1:
The patent replaces electromechanical transducers with an optical sensing system that consumes less energy. The optical sensor detects position through light interaction with the coded surface, eliminating the need for power-intensive electromagnetic fields and copper circuits, thereby reducing energy consumption while maintaining measurement accuracy.
Solution Approach 2:
The coded surface on the rotor serves dual purposes: it is both a mechanical component of the motor and the measurement scale for position detection. This self-service approach eliminates the need for separate powered transducers, reducing energy consumption while providing accurate position feedback.
4Measurement precision
If separate angular position transducers are used, then position feedback is achieved, but cost increases
Solution Approach 1:
The patent merges position feedback functionality into the motor controller assembly, eliminating the need for separate expensive transducers. By integrating the optical sensor, coded surface, and reading mechanism into the motor structure, the invention reduces component count and manufacturing cost while maintaining feedback accuracy.
Solution Approach 2:
The patent uses a simplified optical coding system that replicates the position information function of complex transducers. The coded surface on the rotor provides the necessary position encoding without requiring expensive dedicated transducer hardware, achieving cost-effective position feedback.
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 solution provides a lightweight, cost-effective, and reliable position detection system that enhances safety and energy efficiency by directly integrating the position detection into the electric motor, reducing assembly complexity and improving accuracy while maintaining mechanical performance.
Implementation Method 1
a sensor element, optical or laser, which is arranged integral to the stator and so as to point toward the encoded surface
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An electric actuator apparatus (6) comprising: an electric motor (7), comprising in turn a stator (8) and a rotor (9), which is configured to rotate about an axis (A) according to the power transmitted by the stator (8); a control unit (10) configured to control the electric motor (7) via a feedback control; a position detection system (11) configured to provide the control unit (10) with an angular position of the rotor (9); a reading portion (13), which is integral to the rotor (9) and provided with an encoded surface (14) on which a plurality of codes (15) that can be associated with the angular position of the rotor (9) are fixed; an optical or laser sensor element (16), which is arranged integral to the stator (8) and so as to point toward the encoded surface (14), and wherein the sensor element (16) comprises one or more single-photon, SPAD photodetector (17) diodes.