Vehicle Control System for Driving Force Stability
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Solution Overview
Problem
Existing vehicle systems struggle to suppress variations in driving force during restarts while coasting, failing to appropriately respond to driver requests due to sudden recovery of driving force when the throttle opening degree is higher than a predetermined level.
Innovation Solution
A vehicle control system that prohibits shifting into a state allowing driving force generation based on the accelerator pedal operation until the operation amount decreases below a predetermined value, using a control device to manage the transition between suppressed and active driving force states, thereby regulating driving force variations and responding to driver requests.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the drive system is restarted while the vehicle is coasting with the throttle opening degree higher than the predetermined opening degree, then the driving force can be recovered, but the driving force suddenly recovers steeply causing variation in vehicle driving force
Solution Approach 1:
The control device performs preliminary action by detecting the throttle opening degree before restart and proactively restricting it to at or below the predetermined opening degree. This preliminary restriction prevents the sudden steep recovery of driving force that would occur if restart happened with higher throttle opening, thereby maintaining vehicle driving force stability while still enabling restart functionality.
2Stability of the object's composition
If the throttle opening degree is restricted to at or below the predetermined opening degree during restart, then the variation in vehicle driving force is suppressed, but the response to driver's driving force request is delayed
Solution Approach 1:
The system dynamically adjusts the throttle opening degree restriction based on vehicle conditions. The control device monitors whether the vehicle is in a coasting state and applies the predetermined opening degree restriction only during coasting with drive system stop. When the drive system is operating normally or the vehicle is not coasting, the throttle can open fully to respond immediately to driver requests, thus reducing time loss while maintaining stability when needed.
3Device complexity
If the drive system restarts without checking the throttle opening degree trend, then the restart process is simple, but the driving force output cannot be appropriately controlled when throttle does not decrease after restart
Solution Approach 1:
The control device implements feedback by continuously monitoring the throttle opening degree before, during, and after restart. It detects whether the throttle opening degree is decreasing as expected, and based on this feedback, it determines whether to allow normal restart or prohibit restart to prevent inappropriate driving force output. This feedback mechanism provides appropriate driving force control without excessive complexity.
Data Source
AI summary
A vehicle includes an accelerator pedal, a drive device and an electronic control unit (ECU). The drive device generates driving force for driving a wheel on the basis of an operation amount of the accelerator pedal. The ECU, while the vehicle is travelling in a ready-off state, prohibits a shift into a ready-on state until the operation amount of the accelerator pedal once becomes lower than a predetermined value.