Galvanomagnetic Sensor for Power Lift Gate Strut Position
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current power lift gate systems for vehicles lack accurate detection of lift gate speed and position, especially when the motor speed sensing sensor is powered off, and require additional switches to determine full open and closed positions.
Innovation Solution
A position sensor mounted on a strut with ball and socket end connectors is used to detect the movement of the lift gate, providing rotational and lateral movement data to the vehicle's electronic control unit, eliminating the need for separate switches by using a rotary position sensor or potentiometer to determine the lift gate's position and speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If motor speed sensing device is used to detect lift gate position, then position information can be obtained through calculation, but the position becomes unknown when power is turned off
Solution Approach 1:
The patent replaces the electrical motor speed sensing device with a mechanical rotary position sensor that has no moving parts. The sensor uses a flexible printed circuit board with conductive traces that remain stationary while detecting rotational position through changes in electrical resistance along fixed pathways, eliminating the need for powered motors and maintaining position information without power.
Solution Approach 2:
The rotary position sensor uses the strut's own rotational movement to generate position information passively. The flexible printed circuit board automatically detects position changes through its conductive traces as the strut rotates, without requiring external power sources or additional sensing components, making the system self-sufficient for position detection.
2Measurement precision
If additional switches are added to detect full open and closed positions, then position detection accuracy is improved, but device complexity increases
Solution Approach 1:
The rotary position sensor performs multiple functions simultaneously: it detects full open position, full closed position, and intermediate positions all through a single sensing mechanism. The flexible printed circuit board's conductive traces provide continuous position information across the entire range of motion, eliminating the need for separate switches for different position thresholds.
Solution Approach 2:
The patent combines multiple position detection functions into a single integrated rotary position sensor. Instead of using separate switches for full open, full closed, and intermediate positions, the flexible printed circuit board provides unified position detection for all states through its continuous conductive trace pathways that respond to rotational position changes.
3Measurement precision
If rotary position sensor is used to detect strut movement, then accurate position and speed measurement is achieved, but manufacturing complexity increases
Solution Approach 1:
The patent replaces complex mechanical rotary position sensors with an electrical solution using a flexible printed circuit board. The conductive traces on the flexible PCB provide position detection through changes in electrical resistance or capacitance as the board flexes during rotation, eliminating mechanical wear components and simplifying manufacturing while maintaining measurement precision.
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
The system accurately measures lift gate movement, speed, and full open/closed positions, ensuring reliable operation without additional switches and providing precise control to the power lift gate mechanism.
Implementation Method 1
a galvanomagnetic sensor in the stator portion for detecting angular position of the strut
Data Source
AI summary
A power actuator system for a movable vehicle panel such as a lift gate assembly includes a position sensor that detects the pivotal movement of a strut mechanism of the power lift gate assembly relative to the host vehicle. A rotary sensor is coupled directly to an end component of the strut mechanism and provides signals that indicate the total amount of pivotal or rotary movement of the strut mechanism and the lift gate during the opening and closing of the lift gate. The signals provide information to determine the absolute position of the strut and the lift gate for processing in the vehicle's electronic control unit.