Traction Control Device Torque Limiting for Road Surface Transitions
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Solution Overview
Problem
Existing traction control systems for electric vehicles struggle to rapidly adjust torque settings when the road surface changes, leading to instability and reduced safety during abrupt transitions from dry to frozen or frozen to dry conditions.
Innovation Solution
A traction control device and method that quickly estimates the slip ratio and driving torque using real-time speed and rotational data, calculating a limit value to adjust the torque setting value, ensuring stable operation by limiting the torque when the slip ratio is high and allowing more margin when it's low.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If existing traction control systems use traditional torque adjustment methods, then the system structure remains simple, but the response speed is slow and stability is reduced during abrupt road surface changes
Solution Approach 1:
The patent implements dynamic torque adjustment by continuously monitoring slip ratio and road surface conditions, then rapidly modifying torque settings in real-time. The control system transitions from static torque values to dynamic torque modulation based on actual driving conditions, enabling fast response to abrupt road surface changes while maintaining stability through closed-loop control.
Solution Approach 2:
The patent changes the torque parameter dynamically based on detected slip ratio and road surface friction characteristics. By adjusting the torque setting value according to real-time measurements rather than using fixed torque values, the system achieves both fast response speed and maintained stability during transitions between dry and frozen road surfaces.
2Reliability
If the torque setting value is limited too conservatively, then stability is maintained, but drive power is reduced
Solution Approach 1:
The patent applies dynamic torque limitation that adapts to current driving conditions. When road surface friction is high (dry conditions), the system allows higher torque settings to maintain drive power. When friction decreases (frozen conditions), the system automatically reduces torque limits to prevent slippage. This dynamic adjustment maintains both stability and optimal power delivery across varying conditions.
Solution Approach 2:
The torque limitation parameter is changed dynamically based on detected road surface friction and slip ratio. The control system modifies the maximum allowable torque setting in real-time, permitting aggressive torque application on high-friction surfaces while imposing conservative limits on low-friction surfaces, thereby balancing stability requirements with drive power needs.
3Power
If the torque setting value is increased too aggressively, then drive power is improved, but slippage occurs and stability is compromised
Solution Approach 1:
The patent implements closed-loop feedback control by continuously measuring wheel slip ratio and comparing it against target values. When slippage is detected (excessive slip ratio), the system immediately reduces torque setting to restore traction. When adequate grip is present, the system allows higher torque application. This feedback mechanism prevents aggressive torque application that would cause slippage while maintaining drive power when conditions permit.
4Adaptability or versatility
If traditional torque control methods are used, then the control logic is simple, but the adaptation to changing road conditions is slow
Solution Approach 1:
The patent replaces traditional mechanical or hydraulic torque control mechanisms with electronic control systems that calculate and adjust torque settings computationally. By using sensors to detect wheel speed and slip ratio, then processing this data through control algorithms to determine optimal torque values, the system achieves rapid adaptation to road conditions while keeping the physical actuation mechanism simple (electromagnetic motor control).
Data Source
AI summary
The speed v of a motor driven body, the rotational speed ω and the actual torque value Tm generated by the motor are acquired. Subsequently, unit (741) estimates the slip rate X of the drive wheels based on the movement speed v and the rotation speed ω. Further, unit (742) estimates the drive torque Td based on the rotational speed w and the actual torque value Tm. Next, unit (743) calculates a limit value L for a torque command value Tc based on the slip rate X and the drive torque Td. Further, unit (744) limits the torque command value Tc using the limit value L, generates a torque setting value Ts, which is sent to a motor drive system (900). As a result, it is possible to quickly realize control in accordance with changes in the road surface state, thus allowing safe travel while ensuring the needed drive power.