Variable Speed Closure Panel Controller for Liftgate Reliability
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Solution Overview
Problem
Automated closure panels in vehicles, such as liftgates, often experience unintended reversals or stops due to mechanical variations like misalignment and interference, leading to quality issues and increased servicing needs.
Innovation Solution
A vehicle system with a controller that adjusts the closing speed and latching speed of the liftgate based on past opening and closing forces, using feedback from electric current draws to optimize the closing process and reduce mechanical interference, thereby minimizing false reversals and the need for servicing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed closing speed is used for the automated closure panel, then the control system is simple, but the system experiences unintended reversals or stops due to mechanical variations like misalignment and interference
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed closing speed to a variable closing speed that adapts to mechanical conditions. The controller dynamically adjusts the closing speed based on real-time feedback from current draw sensors, allowing the system to respond to varying mechanical interference levels during operation. This resolves the contradiction by making the control parameter (speed) dynamic rather than static, improving reliability without requiring complex mechanical adjustments.
Solution Approach 2:
The patent implements feedback control by monitoring the current draw of the panel actuator during closing operations and using this information to adjust the closing speed. The controller continuously receives feedback about mechanical interference levels (through current measurements) and modifies the speed command accordingly. This feedback mechanism enables the system to adapt to misalignment and mechanical interference, resolving the reliability issue while keeping the control architecture relatively simple.
2Productivity
If the closing speed is increased to improve productivity, then the closing operation is faster, but mechanical interference and current draw increase causing false reversals
Solution Approach 1:
The system uses dynamic speed adjustment where the closing speed is not fixed but varies based on actual mechanical conditions. When mechanical interference is detected through current draw monitoring, the controller automatically reduces the closing speed to prevent false reversals. This dynamic approach allows the system to maintain high productivity during normal operation while automatically adapting to prevent errors when interference occurs.
Solution Approach 2:
The patent changes the operating parameter (closing speed) based on detected conditions. By monitoring current draw as an indicator of mechanical interference, the system adjusts the speed parameter in real-time. This parameter change strategy allows the closure panel to operate at higher speeds when conditions are favorable, improving productivity, while automatically reducing speed when interference is detected, preventing false reversals and maintaining reliability.
3Reliability
If mechanical components are serviced frequently to maintain alignment, then the closure panel operates reliably, but the maintenance time and cost increase
Solution Approach 1:
The patent implements self-service by enabling the closure panel system to automatically compensate for mechanical misalignment and interference through software-based speed adjustment. Instead of requiring frequent manual servicing to maintain alignment, the system self-adjusts its operating parameters (closing speed) based on real-time feedback from current draw sensors. This eliminates the need for frequent mechanical interventions, maintaining reliability while significantly reducing maintenance time and cost.
Solution Approach 2:
The patent replaces mechanical adjustment mechanisms with an electronic control solution. Rather than requiring physical realignment of latches, strikers, and hinges through manual servicing, the system uses electronic speed control to adapt to mechanical variations. This substitution of mechanical adjustment with electronic adaptation maintains operational reliability while eliminating the need for frequent mechanical maintenance interventions.
Data Source
AI summary
A vehicle system includes a closure panel, one or more panel actuators operable to move the closure panel during opening and closing and to move the closure panel at a closing speed during closing, a latch operable to lock the closure panel, and a controller electrically connected with the panel actuator. The controller is configured to selectively adjust the closing speed of the panel actuator(s) on the next closing, based on past opening and closing of the closure panel. Loss of speed and higher current draws are equated to mechanical interferences in the closing and opening of the closure panel. The speed, voltages, dynamic braking, target speed, and obstacle thresholds can be adjusted in way that facilitates closing the closure panel without the need for servicing.