Electric Vehicle Motor Torque Control for Slope Rollback Prevention
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Solution Overview
Problem
Conventional electric vehicle control systems experience vehicle sliding issues on slope roads during starting operations due to disturbance torque fluctuations, leading to instability and potential rollback.
Innovation Solution
A control device that determines the starting operation of the vehicle, calculates the disturbance torque necessary for maintaining the vehicle's stop state, and adjusts the motor torque responsiveness to quickly converge to the estimated disturbance torque, enhancing the motor's torque responsiveness to gradient disturbances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the disturbance torque rises after vehicle starting operation is performed, then the vehicle can generate braking force, but vehicle sliding occurs on slope roads before disturbance torque is generated
Solution Approach 1:
The control device determines whether the vehicle is in a starting operation state and proactively adjusts the responsiveness of driving torque to disturbance torque before the disturbance torque fully develops. By detecting the starting operation state and pre-adjusting the responsiveness parameter, the system prevents vehicle sliding that would occur during the transient period before disturbance torque is generated.
Solution Approach 2:
The control device dynamically adjusts the responsiveness of driving torque to disturbance torque based on the vehicle's operational state. When a starting operation is detected, the responsiveness is increased to provide faster torque response. This dynamic adjustment allows the system to optimize performance for different operating conditions, ensuring reliable stopping maintenance during starting operations while maintaining appropriate responsiveness during normal operation.
2Reliability
If the responsiveness of driving torque to disturbance is increased, then vehicle sliding is reduced, but the complexity of torque control increases
Solution Approach 1:
The control device changes the responsiveness parameter of driving torque based on the detected vehicle operational state. By adjusting this single parameter according to whether the vehicle is in a starting operation state, the system achieves improved vehicle stability on slopes without requiring complex additional hardware or control mechanisms. The parameter change approach simplifies the solution while effectively addressing the sliding issue.
Solution Approach 2:
The control device uses feedback from the vehicle's operational state (determining whether a starting operation is performed) to adjust the torque control strategy. This feedback mechanism allows the system to automatically adapt its responsiveness to match the current operating conditions, improving stability during critical starting operations while maintaining simpler control during normal operation.
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 effectively reduces the rollback distance and maintains vehicle stability on slope roads by increasing the motor torque's responsiveness to gradient disturbances, ensuring smoother starting operations and reduced anxiety for drivers.
Implementation Method 1
a motor that generates a driving torque and a regenerative torque corresponding to an accelerator operation by a driver
Data Source
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AI summary
The control device for the electric vehicle determines whether or not the starting operation of the vehicle has been performed by the driver, calculates the disturbance torque estimated value Td necessary for maintaining the vehicle stop state corresponding to the disturbance acting on the vehicle, and performs a control such that the driving torque of the motor converges to the disturbance torque estimated value Td when the vehicle is determined to be just before stop of the vehicle during running or determined to have undergone the starting operation. Then, the control device for the electric vehicle controls the responsiveness of the driving torque to the disturbance acting on the vehicle, and increases the responsiveness of the driving torque of the motor compared with the responsiveness of the driving torque just before stop of the vehicle when the starting operation is determined to have been performed.