Reaction Force Apparatus for Gradual Accelerator Control
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Solution Overview
Problem
Existing vehicle speed control systems fail to allow gradual acceleration, as the reaction force applied to the accelerator pedal is reduced when the driver intends to accelerate quickly, leading to excessive pedal depression and inability to increase speed gradually.
Innovation Solution
A reaction force apparatus with a controller that determines the rate of accelerator pedal depression, setting an acceleration intention boundary threshold to differentiate between quick and gradual acceleration, reducing the reaction force only when the rate exceeds this threshold, and maintaining it for gradual acceleration, while also allowing the driver to set and update target vehicle speeds based on intention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the reaction force is reduced when the driver intends to accelerate quickly, then the accelerator pedal becomes lighter and acceleration response is improved, but the driver may depress the pedal more deeply than intended and gradual acceleration becomes impossible
Solution Approach 1:
The reaction force control system dynamically adjusts the reaction force based on the detected acceleration intention. When quick acceleration is detected (rate of depression exceeds threshold), the reaction force is reduced to improve acceleration response. When gradual acceleration is detected (rate of depression below threshold), the reaction force is maintained to preserve pedal control precision. This dynamic adaptation resolves the contradiction by making the system behavior context-dependent.
Solution Approach 2:
The system changes the reaction force parameter based on the detected depression rate. By monitoring the rate of accelerator pedal depression and comparing it to a threshold, the system switches between two reaction force states: reduced reaction force for quick acceleration and maintained reaction force for gradual acceleration. This parameter change enables the system to achieve both fast acceleration response and precise pedal control.
2Ease of operation
If the reaction force is maintained when the driver intends to accelerate gradually, then the driver can control the vehicle speed gradually, but the acceleration response becomes slower
Solution Approach 1:
The system dynamically switches between maintaining and reducing reaction force based on the detected acceleration intention. For gradual acceleration scenarios, the reaction force is maintained to enable precise speed control. For quick acceleration scenarios, the reaction force is reduced to improve response speed. This dynamic behavior allows the system to optimize for the current driving intent.
Solution Approach 2:
The reaction force parameter is changed based on the depression rate threshold comparison. When the rate of depression is below the threshold, the reaction force is maintained at its normal level, enabling gradual speed control. When the rate exceeds the threshold, the reaction force is reduced to improve acceleration response. This conditional parameter change resolves the contradiction.
3Productivity
If the reaction force control is adjusted frequently based on driver intention, then the vehicle speed control becomes more responsive, but the driver comfort decreases due to frequent changes
Solution Approach 1:
The system uses a threshold-based parameter change approach rather than continuous adjustment. By comparing the depression rate to a fixed threshold, the system makes discrete reactions force adjustments only when the driver's intention clearly indicates quick acceleration. This avoids frequent minor adjustments that would cause discomfort while maintaining responsive control when needed.
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
A reaction force apparatus (12) incorporated in a vehicle includes a reaction force controller (28) for setting an acceleration intention boundary threshold value (THvθ), which comprises a threshold value with respect to a rate of depression (Vθ) of an accelerator pedal, and which determines whether the driver of the vehicle intends to accelerate the vehicle quickly or gradually. The reaction force controller (28) reduces the reaction force (Fr) when the rate of depression (Vθ) exceeds the acceleration intention boundary threshold value (THvθ), whereas the reaction force controller (28) maintains the reaction force (Fr) when the rate of depression (Vθ) is less than the acceleration intention boundary threshold value (THvθ).