Wheel-Spin Torque Control Unit With Gradual Inverter Current Regulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric motorcycles face hazards such as loss of traction and unintended acceleration/deceleration due to wheel spin, necessitating improved torque regulation to meet ISO 26262 safety standards.
Innovation Solution
A control unit monitors maximum and minimum torque values and gradients to regulate torque during wheel spin, using a logic circuitry and software to manage phase currents, ensuring safe torque limits and gradual adjustments to prevent unintended vehicle motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If torque is reduced to prevent wheel spin, then wheel spin is prevented, but unintended vehicle deceleration occurs
Solution Approach 1:
The control unit dynamically adjusts the torque reduction strategy by monitoring wheel spin conditions in real-time. When wheel spin is detected, the control unit reduces torque gradually rather than abruptly, and continuously adapts the reduction magnitude based on ongoing wheel speed measurements, preventing both wheel spin and unintended deceleration
Solution Approach 2:
The system implements a feedback mechanism where the control unit continuously monitors wheel speed and detects wheel spin conditions, then uses this feedback to adjust torque reduction commands. The control unit compares actual wheel speed against expected speed and modifies torque delivery accordingly, ensuring stable vehicle deceleration while preventing wheel spin
2Reliability
If torque is increased to prevent loss of traction, then traction is improved, but unintended vehicle acceleration occurs
Solution Approach 1:
The control unit dynamically modulates torque delivery based on real-time traction conditions. When loss of traction is detected through wheel speed monitoring, the control unit increases torque gradually and continuously adjusts the magnitude based on ongoing feedback, maintaining optimal traction while preventing unintended acceleration
Solution Approach 2:
The system uses feedback from wheel speed sensors to detect loss of traction conditions and adjusts torque delivery accordingly. The control unit continuously monitors wheel acceleration and modifies torque commands to maintain traction while preventing unintended vehicle acceleration
3Device complexity
If torque regulation is simplified by monitoring only max and min values, then device complexity is reduced, but safety compliance becomes difficult
Solution Approach 1:
The control unit serves multiple safety functions within a single integrated device. It monitors torque values, detects wheel spin conditions, calculates gradient changes, and executes torque regulation commands all through one control unit, maintaining safety compliance without requiring separate complex monitoring systems
Data Source
Figure 1
Figure 2
AI summary
The control unit (10) detects a wheel (11) spin based on a variation in a vehicle parameter and activates a traction control module (14) to calculate and reduce a demanded torque during the wheel spin moment. The control unit (10) calculates a target torque from multiple vehicle parameters and is provided as a desired torque from an inverter unit (16) after comparing the target torque with the demanded torque. The control unit (10) regulates the desired torque in a sequential steps by controlling required phase currents by the inverter unit (16).