In-Wheel Motor Torque Switching for Reliability Under State Variation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing technologies fail to address the decrease in reliability of electric motors independently driving vehicle wheels due to variations in operation rate and state, such as temperature and magnetic flux, leading to potential reliability issues.
Innovation Solution
An electric motor control device that includes a control information transmission/reception unit, an electric motor state acquisition unit, and a torque command switching unit to adjust torque commands based on vehicle driving state and motor state information, switching between original and corrected torque commands to stabilize operation rates and temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If independent control of in-wheel motors is implemented to improve traveling performance and safety, then wheel slip suppression and road adaptation are improved, but variation in operation rate between motors increases leading to decreased reliability
Solution Approach 1:
The control device acquires operation rate information from each in-wheel motor and uses this feedback to dynamically adjust torque commands. The control information transmission/reception unit receives operation rate information, and the control processing unit adjusts torque distribution based on this feedback, ensuring balanced operation rates and preventing reliability degradation from excessive operation rate variation.
2Temperature
If torque command is increased for upstream motor in coolant circulation path, then cooling efficiency is improved, but this approach does not address reliability decrease due to driving state variations
Solution Approach 1:
The control device dynamically changes torque command parameters based on real-time operation rate information. Instead of fixed torque distribution or simple coolant path-based adjustment, the system modifies torque commands according to actual motor operation rates, temperature conditions, and driving states, achieving comprehensive reliability improvement through multi-parameter adaptive control.
3Productivity
If operation rate of electric motor is increased to meet driving demands, then vehicle performance is improved, but reliability of electric motor decreases due to high operation rate
Solution Approach 1:
The control device dynamically adjusts torque commands based on real-time operation rate information from each motor. Rather than static torque distribution, the system continuously adapts torque allocation to maintain balanced operation rates across motors, optimizing vehicle performance while preventing any single motor from excessive operation that would degrade reliability.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An object of the present invention is to suppress a decrease in reliability of each electric motor that independently drives each wheel of a vehicle. An electric motor control device 3 is a device that controls each electric motor 2 that independently drives each wheel 1 of a vehicle 10. The electric motor control device 3 includes: a control information transmission/reception unit 31 that receives, from a higher-level control device 4, control information 41 including a torque command 412 for the electric motor 2 and driving state information 411 regarding a driving state of the vehicle 10; an electric motor state acquisition unit 32 that acquires electric motor state information 321 regarding a state of the electric motor 2; and a torque command switching unit 33 that switches between controlling the electric motor 2 according to the torque command 412 and controlling the electric motor 2 according to a corrected torque command 371 obtained by correcting the torque command 412 based on the control information 41 received from the higher-level control device 4 and the electric motor state information 321 acquired by the electric motor state acquisition unit 32.