Idle-Stop Brake Pressure Estimation Without Pedal Sensors
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Solution Overview
Problem
Existing idling stop devices for vehicles are complicated due to the need for multiple sensors to detect brake pressure and pedal stroke, which increases the system's complexity.
Innovation Solution
An idling stop device that uses a deceleration detection system to estimate brake pressure based on vehicle deceleration, weight, and brake efficiency, eliminating the need for sensors that detect brake liquid pressure or pedal stroke, and incorporating a gradient detection system to account for road surface gradients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sensors such as a brake liquid pressure sensor or a brake pedal stroke sensor are provided to detect brake pressure, then the accuracy of brake pressure detection is improved, but the device complexity increases
Solution Approach 1:
The patent replaces mechanical sensors (brake liquid pressure sensor, brake pedal stroke sensor) with a deceleration detection system. The control unit calculates brake pressure by detecting vehicle deceleration and using the relationship between deceleration and brake pressure, thereby eliminating the need for complex mechanical sensing components while maintaining measurement capability.
Solution Approach 2:
The patent introduces deceleration as an intermediary parameter to indirectly measure brake pressure. Instead of directly sensing brake pressure, the system detects deceleration (caused by brake application) and uses this intermediate measurement to calculate the actual brake pressure, simplifying the direct measurement requirement.
2Reliability
If multiple sensors are mounted on the vehicle to detect brake operation amount, then the reliability of brake pressure acquisition is improved, but the manufacturing cost and device complexity increase
Solution Approach 1:
The patent makes the deceleration detection system serve multiple functions: it detects vehicle deceleration for normal operation and simultaneously serves as the basis for calculating brake pressure for idling stop control. This multi-functional approach eliminates the need for dedicated brake pressure sensors, reducing component count while maintaining reliability.
Solution Approach 2:
The system uses the vehicle's existing deceleration detection capability (which would be present for other vehicle control functions) to also perform brake pressure measurement for idling stop control. The system serves itself by utilizing already-available data rather than requiring additional specialized sensors.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Simplifies the idling stop device constitution by performing idling stop control without additional sensors, ensuring proper engine stop and restart conditions based on estimated brake pressure, and considering road gradients for effective brake pressure management.
Implementation Method 1
a detection part which detects deceleration of a vehicle
Implementation Method 2
a brake pressure control part which maintains a brake pressure by closing a valve provided to a brake pipe passage through which a master cylinder constituting a generation source of a brake liquid pressure applied to a vehicle and a wheel cylinder of a wheel communicate with each other
Data Source
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AI summary
Provided is a technique for simplifying the structure of an idling stop device. The idling stop device 100 includes a deceleration detector 200 which detects deceleration of a vehicle. The idling stop device 100 also includes an estimation part 350 which acquires, based on the deceleration detected by the deceleration detector 200, first deceleration when a vehicle is decelerated to a preset speed or less. Based on the acquired first deceleration, the estimation part 350 estimates a first brake pressure applied to the vehicle when the vehicle is decelerated to the preset speed or less. The idling stop device 100 also includes: an ISC 400 which stops an engine of the vehicle when the first brake pressure estimated by the estimation part 350 is higher than or equal to a preset threshold value; and an ESP 300 which transmits a valve opening/closing control signal to a hydraulic circuit 10 so as to maintain the brake pressure.