Brake Control Device for Bar Handle Vehicles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In vehicles with bar handles, such as motorcycles, the estimated vehicle body speed calculation during cornering is inaccurate due to the application of a preset constant deceleration similar to the straight traveling state, affecting the execution of ABS control.
Innovation Solution
A brake control device that includes a wheel speed obtaining unit, an estimated vehicle body speed setting unit, and a bank angle obtaining unit, which corrects the deceleration limit value based on the bank angle to accurately calculate the estimated vehicle body speed during cornering, ensuring precise fluid pressure control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a preset constant deceleration is applied to calculate estimated vehicle body speed during cornering (similar to straight traveling state), then the calculation method is simple and unified, but the estimated vehicle body speed becomes inaccurate affecting ABS control execution
Solution Approach 1:
The patent applies dynamics by making the deceleration limit value changeable based on vehicle state. Instead of using a fixed preset constant deceleration for all conditions, the system dynamically adjusts the deceleration limit value according to whether the vehicle is in a cornering state (determined by bank angle threshold). When cornering is detected, a smaller deceleration limit value is used; when not cornering, a larger preset constant deceleration value is applied. This resolves the contradiction by adapting the calculation complexity to the actual operating conditions.
Solution Approach 2:
The patent implements parameter changes by modifying the deceleration limit value parameter based on the bank angle parameter. The system obtains the bank angle, compares it against a threshold to determine cornering state, and accordingly changes the deceleration limit value parameter. This allows the estimated vehicle body speed calculation to accurately reflect the actual vehicle dynamics during cornering while maintaining a relatively simple calculation framework, thus improving measurement precision without excessive complexity.
2Measurement precision
If the deceleration limit value is corrected based on bank angle to improve estimated vehicle body speed accuracy, then the estimated vehicle body speed becomes more accurate for ABS control, but the system complexity increases due to additional sensors and calculations
Solution Approach 1:
The patent applies universality by making the bank angle sensor serve multiple functions. The same bank angle sensor and its data are used not only for detecting cornering state to adjust the deceleration limit value, but also for other vehicle control functions such as stability control and traction control. This multi-functional use justifies the addition of the sensor and reduces the overall system complexity impact, as the hardware investment serves multiple purposes beyond just the estimated vehicle body speed calculation.
Solution Approach 2:
The patent uses the bank angle as an intermediary parameter to indirectly obtain information about vehicle dynamics during cornering. Instead of directly measuring complex multi-axis accelerations or using multiple sensors to capture the full vehicle state, the system uses the bank angle (obtainable from a single inclination sensor) as an intermediary to infer cornering conditions and adjust the deceleration limit value accordingly. This intermediary approach simplifies the measurement system while achieving the goal of accurate estimated vehicle body speed calculation during cornering.
Data Source
AI summary
A brake control device for vehicles with bar handle includes: a wheel speed obtaining unit obtaining a speed of a wheel; an estimated vehicle body speed setting unit setting an estimated vehicle body speed; a control unit performing fluid pressure control to raise, reduce or hold a brake fluid pressure; and a bank angle obtaining unit obtaining a bank angle. The estimated vehicle body setting unit sets a limit value of a change amount when the estimated vehicle body speed decreases at a time of braking of the vehicle, and sets the estimated vehicle body speed based on the limit value when a deceleration amount of the speed of the wheel on a braked side is larger than the limit value, and the estimated vehicle body speed setting unit corrects the limit value so that the change amount decreases as the obtained bank angle increases.