Roof Motor Feedforward Control for Smooth Panel Movement

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Solution Overview

Problem

The smooth operation of a movable panel or sun blind in a vehicle roof assembly is hampered by environmental factors such as temperature and humidity, and aging, which affect the motor control, leading to fluctuations in speed and potentially unstable behavior.

Innovation Solution

A control system incorporating a speed controller, current controller, and performance feed forward module that uses feedback and feed forward mechanisms to adjust motor control based on stored performance profiles for various operating conditions, including relative and absolute positions, to maintain consistent speed and torque.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional feedback control is used to maintain motor speed, then the system structure remains simple, but the smooth operation deteriorates under environmental factors and aging

Engineering Contradiction:
Improvesmooth operationVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system performs preliminary action by storing performance profiles (torque/current vs. position data) obtained under various operating conditions before actual operation. When environmental factors or aging affect the system, the pre-stored profiles enable the controller to proactively adjust motor parameters without real-time feedback delays, maintaining smooth operation from the outset rather than reacting to deviations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system applies parameter changes by dynamically adjusting motor control parameters (torque, current) based on the selected performance profile corresponding to current operating conditions. The controller modifies these parameters as a function of absolute position, allowing the motor to adapt to changing environmental factors and aging effects while maintaining consistent performance characteristics.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If performance profiles are stored for multiple operating conditions, then adaptability to environmental factors improves, but memory requirements and processing complexity increase

Engineering Contradiction:
Improveadaptability to operating conditionsVSAvoidmemory storage requirements
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The system applies partial action by storing performance profiles for representative operating conditions rather than attempting to cover every possible scenario. The controller selects the most appropriate profile based on current conditions, using only the necessary subset of stored data. This approach provides sufficient adaptability for practical environmental variations while avoiding the excessive memory requirements of storing complete coverage for all conceivable conditions.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If feedback control alone is used, then the control system remains simple, but speed fluctuations occur due to environmental factors and aging

Engineering Contradiction:
Improvespeed consistencyVSAvoidcontrol mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system combines feedback control with feedforward performance profiles. The feedback mechanism continuously monitors actual motor performance and compares it with the target trajectory defined by the selected performance profile. This dual approach maintains speed consistency by using feedback to correct deviations while the pre-stored profiles provide the optimal reference trajectory that anticipates environmental and aging effects.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The performance profiles represent preliminary action by pre-calculating and storing the optimal torque/current trajectories needed to maintain smooth operation under various conditions. This preliminary preparation allows the system to anticipate and compensate for environmental factors and aging before they cause speed fluctuations, reducing reliance on reactive feedback control alone.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4675908A1Control system of a motor for a roof assembly and method therefor
Publication Date: 2026.01.07 INALFA ROOF SYST GROUP
  • EP4675908A1 patent drawingFigure 1A~1B
  • EP4675908A1 patent drawingFigure 2~4
  • EP4675908A1 patent drawingFigure 5

AI summary

The invention relates to a control system for a motor operating a roof assembly, including a speed controller, a current controller, a motor and a performance feed forward module. The control system is configured for receiving a speed setpoint as input, feeding back a speed signal, and determining a speed error. Providing a current setpoint and feeding back a current output to the current setpoint, and providing a current error signal to the current controller. Feeding back a relative position signal and feeding forward, based on at least one performance profile determined from an absolute position signal, a current feed forward signal to the current setpoint. And generating, based on the current error signal and the relative position signal, a drive signal for driving a motor. The current error signal is based on the current setpoint, the current feedback and the current feed forward.