Vehicle Joystick Control for Precise Braking Force
Solution Overview
Problem
Current vehicle operating devices with a joystick configuration lack precision in applying braking force, failing to accurately reflect the driver's intention, especially in situations requiring sudden braking, and do not effectively manage vehicle state transitions between forward and backward motion.
Innovation Solution
An operating device that allows for directional operations from a neutral position to apply drive force in either direction, with the ability to adjust braking force magnitude based on the operation amount, and includes mechanisms for regenerative braking and neutral-position-dependent braking to maintain vehicle stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single joystick operating member is used to control both acceleration and braking, then the number of operating members is reduced, but the precision of braking force control deteriorates
Solution Approach 1:
The patent segments the braking control function by introducing two distinct operating modes: normal braking mode (joystick within dead zone) and emergency braking mode (joystick exceeding dead zone). This segmentation allows the system to differentiate between routine braking and emergency stopping requirements, improving braking force control precision without adding physical operating members.
Solution Approach 2:
The patent implements dynamic control of braking force based on the joystick's operation amount. The braking force magnitude is dynamically adjusted according to how far the joystick is operated beyond the dead zone, enabling continuous variation of braking force from mild to emergency levels. This dynamic response restores precision to braking control while maintaining the single joystick interface.
2Ease of operation
If the joystick is operated in the second direction beyond neutral position while vehicle is running forward, then braking force is applied, but the braking force magnitude does not reflect driver's intention
Solution Approach 1:
The patent incorporates feedback through the dead zone mechanism, where the joystick's position relative to the dead zone provides information about the driver's braking intention. When the joystick exceeds the dead zone, the system interprets this as emergency braking intent and applies corresponding strong braking force. This feedback loop ensures the braking force magnitude accurately reflects the driver's intention.
Solution Approach 2:
The patent changes the operational parameters of the joystick by introducing a dead zone threshold. Operations within the dead zone produce normal braking force, while operations exceeding the dead zone produce emergency braking force. This parameter change allows the single joystick to reliably convey different levels of braking intention, with the dead zone serving as a clear distinction point between normal and emergency braking scenarios.
3Stability of the object's composition
If conventional braking control is used with joystick at neutral position, then the vehicle stops, but sudden braking cannot be applied when required
Solution Approach 1:
The patent prepares the braking system for sudden braking by establishing the dead zone as a pre-defined threshold. The driver is implicitly trained that operating the joystick beyond this threshold will trigger emergency braking. This preliminary setup allows immediate transition to strong braking force when needed, without requiring additional steps or time delays, thus improving braking response speed while maintaining normal stopping stability.
Solution Approach 2:
The dead zone mechanism serves as a preliminary anti-action by preventing accidental emergency braking while enabling intentional emergency braking. The dead zone acts as a buffer that filters out minor joystick movements, ensuring stable normal braking, while clearly defined exceedance of this zone triggers the opposite effect—emergency braking. This dual nature resolves the contradiction between stability and rapid response capability.
Data Source
AI summary
A vehicle operating device including an operating member operable by a driver and configured to: issue, to a drive system, a command to apply a drive force in a forward direction when a first-direction operation of the operating member from its neutral position in a first direction is performed in a state in which the vehicle is at a stop or running forward; issue, to the drive system, a command to apply a drive force in a backward direction when a second-direction operation of the operating member from the neutral position in a second direction different from the first direction is performed in a state in which the vehicle is at a stop or running backward; and issue, to a brake system, a command to apply a braking force as an opposite-direction-operation-dependent braking force when the second-direction operation is performed in a state in which the vehicle is running forward.