Insertion Device Motor Control Switching Speed to Torque

Solution Overview

Problem

Existing insertion devices, such as self-propelled endoscopes, face limitations in torque control, where the motor torque limit function stops rotation when exceeding a predetermined value, leading to inefficiencies in insertion and removal operations.

Innovation Solution

A control apparatus that employs a dual control method, switching from speed control to torque control when the drive current reaches a predetermined value, allowing the motor to maintain a targeted current value within the torque limit, preventing frequent activation of the torque limit function and optimizing motor operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a torque limit function is used to stop motor rotation when torque exceeds a predetermined value, then motor protection is achieved, but insertion and removal operations become inefficient due to frequent stopping

Engineering Contradiction:

Improvemotor protectionVSAvoidinsertion and removal efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies dynamics by switching between two control modes (speed control and torque control) based on operating conditions. The controller dynamically adjusts the control strategy: using speed control when drive current is below the switching value to maintain high rotation speed for efficient insertion/removal, and switching to torque control when drive current reaches the switching value to prevent torque limit activation. This dynamic adaptation resolves the contradiction between motor protection and operational efficiency.

Inventive Principle:

Principle #15Dynamics

2Speed

If speed control method is used to maintain targeted rotation speed, then insertion speed is improved, but motor current may exceed torque limit causing frequent stoppings

Engineering Contradiction:

Improveinsertion speedVSAvoidtorque limit compliance

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The patent implements feedback control by continuously monitoring the drive current value and comparing it against a predetermined switching value. When the drive current reaches the switching value during speed control, the system switches to torque control to maintain current below the torque limit threshold. This feedback mechanism ensures that speed control operates within safe current boundaries, preventing torque limit activation while maintaining high insertion speeds during normal operation.

Inventive Principle:

Principle #23Feedback

3Reliability

If torque control method is used to maintain current below torque limit, then motor protection is improved, but rotation speed varies under varying loads reducing insertion efficiency

Engineering Contradiction:

Improvetorque limit complianceVSAvoidinsertion speed consistency

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The patent applies dynamics by switching between two control modes (speed control and torque control) based on operating conditions. The controller dynamically adjusts the control strategy: using speed control when drive current is below the switching value to maintain high rotation speed for efficient insertion/removal, and switching to torque control when drive current reaches the switching value to prevent torque limit activation. This dynamic adaptation resolves the contradiction between motor protection and operational efficiency.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS11096561B2Control apparatus for insertion device and insertion device

Publication Date: 2021.08.24 OLYMPUS CORPORATION(JP)

AI summary

A control apparatus includes a drive current detector detecting a drive current value driving the motor to drive a rotation body, and a controller controlling the motor in a speed control method which controls the motor so that a rotation speed of the motor reaches a targeted rotation speed until the drive current value reaches a predetermined switching value, and, when the drive current value reaches the switching value, controlling the motor by switching to a torque control method which controls the motor so that the drive current value reaches a targeted current value.