Vehicle Accelerator Pedal Reaction Force Control
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Solution Overview
Problem
Existing vehicle control systems fail to provide drivers with sufficient and instinctive perception of the accelerator pedal operation, particularly at varying depression speeds, leading to discrepancies between actual and perceived reaction forces.
Innovation Solution
A vehicle control device with a depression amount detection unit, depression speed detection unit, and reaction force setting unit that separates reaction force characteristics into advancement and return characteristics, adjusting the reaction force to ensure linear continuity and perception, using a three-dimensional map defined by depression amount, speed, and muscle activity to optimize pedal operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a substantially proportional relationship is set between depression amount and reaction force value, then the driver can recognize depression amount by reaction force value, but the driver cannot experience operation linearity at varying depression speeds
Solution Approach 1:
The patent applies dynamics by making the reaction force characteristics variable based on depression speed. The control device dynamically adjusts the reaction force value according to the detected depression speed, transitioning from a static proportional relationship to a dynamic adaptive relationship. This allows the system to maintain measurement precision across different operating conditions while preserving operation linearity perception.
Solution Approach 2:
The patent changes the parameter of reaction force value based on depression speed parameter. By introducing depression speed as an additional parameter and adjusting reaction force accordingly, the system resolves the contradiction between maintaining accurate depression amount recognition and ensuring operation linearity perception across varying speeds.
2Device complexity
If reaction force value is applied by electric actuator in drive-by-wire system, then cable connection is eliminated, but the natural feedback relationship between pedal and driver is disrupted
Solution Approach 1:
The patent implements feedback by using sensors to detect depression amount and depression speed, then using this information to adjust the reaction force value through the electric actuator. This closed-loop feedback system restores the natural feedback relationship between pedal operation and driver perception, compensating for the disruption caused by eliminating the cable connection.
Solution Approach 2:
The control device acts as an intermediary between the electric actuator and the driver. It processes sensor data and generates appropriate reaction force commands, mediating the interaction to create a natural-feeling connection despite the absence of direct mechanical coupling.
3Ease of operation
If reaction force characteristics are set to be suitable for specific driving environment, then driver burden is alleviated, but the system lacks adaptability to varying depression speeds
Solution Approach 1:
The patent makes the reaction force characteristics dynamic by continuously adjusting them based on real-time depression speed detection. This allows the system to adapt to varying depression speeds while maintaining suitability for different driving environments, resolving the contradiction between burden reduction and adaptability.
Data Source
AI summary
A vehicle control device includes a depression amount detection unit, a depression speed detection unit, a reaction force setting unit, and a reaction force generation unit. The reaction force setting unit sets a value of a reaction force in a manner of separating characteristics into advancement characteristics and return characteristics. The reaction force setting unit sets a value of a reaction force with respect to a depression amount in such a way that, in main advancement characteristics except for both ranges corresponding to start of depressing and end of depressing among advancement characteristics, a degree of increase of a value of a reaction force relatively decreases, as a depression amount increases until a predetermined ratio with respect to a maximum depression amount of an accelerator pedal reaches, and a degree of increase of a value of a reaction force relatively increases, as a depression amount increases after the predetermined ratio reaches; and sets a value of the reaction force in such a way that a value of the reaction force decreases, as a depression amount decreases.