Electric Vehicle Speed Controller Using Dynamic Torque Compensation
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Solution Overview
Problem
Electric vehicles face instability and speed control challenges, particularly when navigating slopes and turns, due to the coupling of steering and balancing controls, which can lead to loss of balance and reduced braking capability.
Innovation Solution
A computerized method and controller system that determines steady-state torque and torque during acceleration and deceleration, using measured actuator current and vehicle weight to modulate speed, with a pitch controller adjusting the maximum allowable speed based on acceleration-compensated average current and regeneration current, ensuring stable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the vehicle operates at high speed on slopes, then productivity is improved, but stability deteriorates due to loss of balance
Solution Approach 1:
The patent implements dynamic speed limiting by continuously monitoring actuator current and regeneration current to adjust the maximum allowable speed in real-time. The system transitions from static speed limits to dynamic speed adjustment based on actual operating conditions, allowing the vehicle to maintain stability while optimizing speed on slopes
Solution Approach 2:
The system uses feedback from actuator current sensors and regeneration current measurements to continuously adjust speed limits. The controller monitors the difference between measured actuator current and acceleration-compensated average current to determine when to apply speed limiting, creating a closed-loop control system that maintains stability
2Productivity
If the vehicle accelerates or decelerates rapidly, then productivity is improved, but reliability deteriorates due to loss of braking capability
Solution Approach 1:
The system performs preliminary compensation by calculating acceleration-compensated average current before determining speed limits. This anticipatory calculation allows the system to reserve sufficient actuator capability for braking by accounting for acceleration demands in advance, ensuring braking capability is maintained even during rapid acceleration or deceleration
Solution Approach 2:
The patent changes the parameter used for speed limiting from raw actuator current to acceleration-compensated average current. This parameter transformation separates acceleration-related current consumption from braking-related current consumption, allowing the system to maintain reliable braking capability while preserving acceleration performance
Data Source
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AI summary
A controller and methods for controlling the speed of a vehicle having an electric motorized drive is provided. In one embodiment, a method involves determining a steady state average torque and a torque during acceleration or deceleration of the vehicle traveling over an underlying surface. Speed of the vehicle is controlled based on the steady state average torque, the torque during acceleration or deceleration the measured regeneration current generated by a motorized drive arrangement of the vehicle that applies torque to at least one ground-contacting element of the vehicle for traveling over the underlying surface, weight of the vehicle and pay load, the torque applied to the ground-contacting element, acceleration of the vehicle and the speed of the vehicle.