Vehicle Seat Motor Control via Position-Adaptive Speed Mapping

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Solution Overview

Problem

Existing motor control systems for vehicles, such as seat mechanisms, face challenges in achieving unified movement without being influenced by the operation starting position and are sensitive to environmental changes like ambient temperature and power voltage fluctuations, leading to discomfort and inefficiencies in operation time.

Innovation Solution

A motor control device with an acceleration portion to increase target rotations, a deceleration portion to decrease rotations, and a main control portion to manage motor drive based on target rotations set according to the object's position, ensuring smooth and unified movement while resisting environmental influences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If slow start control and slow down control are executed to avoid impact noise and uncomfortable vibration, then the movable portion can be smoothly started and stopped, but the total operation time increases

Engineering Contradiction:
Improvesmooth start and stopVSAvoidtotal operation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies dynamics by making the motor control adaptable to different operating conditions. The control device dynamically adjusts the target rotational speed based on the driven object's position, using a map that varies parameters according to the operation phase (start, middle, end). This allows the system to optimize between smooth operation and time efficiency for each specific condition rather than using fixed slow start/slow down control throughout.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes parameters by using a map-based control system where the target rotational speed, acceleration rate, and deceleration rate are not fixed but vary according to the driven object's position and operation phase. The map stores multiple sets of parameters that are selected based on current conditions, enabling the system to achieve both smooth operation and reduced total time by optimizing parameters for each phase of movement.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If control is executed based on a fixed target number of rotations determined by seat position, then the motor can be controlled accurately, but the vehicle seat may not move in unity when the starting position varies and the user may feel discomfort

Engineering Contradiction:
Improvemotor control accuracyVSAvoidunified movement across different starting positions
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent makes the control system dynamic by adjusting the target rotational speed based on the driven object's position. Instead of using a fixed target number of rotations, the system continuously adapts the control parameters according to the current position and operation phase, ensuring unified movement appearance regardless of where the operation starts. The map-based approach allows real-time parameter adjustment to maintain visual consistency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies preliminary action by pre-calculating and storing optimal control parameters in a map for various operation phases and positions. Before executing the movement, the system determines the appropriate parameters based on the current state, allowing it to anticipate and compensate for variations in starting positions. This preparatory setup enables consistent unified movement appearance across different operating conditions.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the motor is operated at high rotational speed to shorten operation time, then productivity increases, but impact noise and uncomfortable vibration occur when the movable portion reaches the end-point

Engineering Contradiction:
Improveoperation speedVSAvoidimpact noise and vibration
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent applies dynamics by continuously adjusting the target rotational speed based on the driven object's position and operation phase. The system transitions from higher speeds during the middle phase to lower speeds during the end phase, as defined in the map. This dynamic adjustment allows the motor to operate at high speeds when safe to do so (maintaining productivity) while automatically reducing speed to prevent impact noise and vibration when approaching the endpoint.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses periodic action by dividing the operation into distinct phases (start phase, middle phase, end phase) with different speed characteristics. The map-based control systematically varies the target rotational speed according to which phase the system is in, creating a rhythmic pattern of acceleration and deceleration that maintains high overall productivity while ensuring smooth deceleration at critical moments to avoid harmful impacts and noise.

Inventive Principle:
Principle #19Periodic action

4Productivity

If feedforward control is used to execute operations quickly, then productivity increases, but a great difference between actual and target rotational speeds occurs due to slide resistance variations and temperature changes

Engineering Contradiction:
Improveoperation speedVSAvoidrotational speed accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies parameter changes by using a map that stores target rotational speed values adjusted for different operating conditions including temperature and load variations. Instead of using a single feedforward parameter, the system selects from multiple pre-calibrated parameter sets based on current conditions. This allows the feedforward control to remain fast and responsive while compensating for environmental factors like slide resistance and temperature that affect actual rotational speed.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2287038B1Motor control device and seat control device for vehicle
Publication Date: 2019.04.10 AISIN SEIKI KK
  • EP2287038B1 patent drawingFigure 1
  • EP2287038B1 patent drawingFigure 2A
  • EP2287038B1 patent drawingFigure 2B

AI summary

A motor control device (10) includes an acceleration portion (2) for increasing a target number of rotations (VT) of a motor (30) every predetermined calculation cycle until the target number of rotations (VT) of the motor (30) reaches an upper limit number of rotations (VL), which is set on the basis of a reached position of a driven object from a reference position, the driven object is driven by the motor (30) so that a position of the driven object is changed, a deceleration portion (4) for decreasing the target number of rotations (VT) of the motor (30) every calculation cycle after the target number of rotations (VT) reaches the upper limit number of rotations (VL), and a main control portion (1) for controlling a drive of the motor (30) on the basis of the target number of rotations (VT).