Vehicle Control Device Slip Detection via Speed Feedback
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Solution Overview
Problem
Existing vehicle slip suppression control systems face issues with inaccurate and delayed intervention due to sensor noise and road surface irregularities, leading to unnecessary slip suppression control, which can be exacerbated by factors like error in pulse interval and vehicle body vibrations.
Innovation Solution
A vehicle control device that includes a speed calculation unit, a speed estimation unit, and a slip estimator, which compares calculated and estimated speeds to determine if slip suppression control is necessary, using a motion feedback calculation unit with a proportional gain to adjust and correct the calculation speed, thereby reducing erroneous determinations and enabling quicker and more accurate intervention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a low-pass filter is used to reduce noise in acceleration detection, then measurement precision is improved, but response time deteriorates due to detection delay
Solution Approach 1:
The patent introduces a model-based acceleration calculator that acts as an intermediary between raw sensor data and control decisions. Instead of directly using noisy sensor acceleration data, the system calculates expected acceleration from the difference between actual and model-predicted wheel speeds, thereby filtering noise while maintaining fast response to genuine slip conditions
Solution Approach 2:
The system employs feedback by continuously comparing model-predicted wheel speeds with actual sensor measurements. The acceleration calculator uses this feedback loop to determine whether detected acceleration represents genuine slip conditions or merely sensor noise, enabling accurate noise rejection without delay
2Speed
If slip suppression control is performed based on raw acceleration data, then response speed is improved, but reliability deteriorates due to erroneous detection from noise and road irregularities
Solution Approach 1:
The model-based acceleration calculator serves as an intermediary that processes raw sensor data through a physical model of wheel dynamics. This intermediary layer filters out erroneous signals from noise and road irregularities while preserving genuine slip detection, thereby improving reliability without sacrificing response speed
Solution Approach 2:
The patent replaces direct mechanical sensor-based acceleration detection with a model-based calculation system. Instead of relying solely on physical acceleration sensors that are susceptible to noise, the system substitutes a computational model that predicts expected acceleration based on wheel speed dynamics, thereby improving detection reliability
Data Source
AI summary
The vehicle control device includes a speed calculation unit, a speed estimation unit, a motion feedback calculation unit, and a slip estimator. The speed calculation unit calculates a speed in a predetermined direction of a vehicle on the basis of a feature quantity. The speed estimation unit estimates a speed in the predetermined direction on the basis of a speed or acceleration detected by a motion detector. The motion feedback calculation unit performs feedback calculation in which a value obtained, through a proportional gain, from a deviation between a calculation speed calculated by the speed calculation unit and an estimation speed estimated by the speed estimation unit, is added to the feature quantity. The slip estimator compares the calculation speed with the estimation speed, and estimates that the vehicle is in a slip state in the predetermined direction, when the estimation speed exceeds the calculation speed.