Brake Drive Control Circuit with Series Semiconductor Switching and Test Pulse Detection

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Solution Overview

Problem

Existing brake drive control circuits cannot continuously test for malfunctions during robot operation, leading to potential double faults and safety risks, especially when high reliability and long-term continuous operation are required.

Innovation Solution

A brake drive control circuit with semiconductor circuits connected in series, control devices generating brake signals, and a voltage detection circuit that introduces test pulses to detect malfunctions during brake engagement and disengagement, allowing for periodic testing of semiconductor circuits during robot operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If semiconductor circuits are used for brake drive control to enable high frequency engagement/disengagement, then the brake can operate during temporary stops, but the semiconductor circuit becomes vulnerable to malfunction and short-circuiting

Engineering Contradiction:

Improvebrake engagement/disengagement frequencyVSAvoidsemiconductor circuit reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The brake drive control circuit is divided into two independent semiconductor switching devices (Tr1 and Tr2) connected in series, each controlled by separate control signals (BS1 and BS2). This segmentation allows the system to tolerate a malfunction in one device while the other can still function, thereby maintaining brake operation during temporary stops while improving fault tolerance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A detection circuit is incorporated that continuously monitors the brake circuit status before and during operation. The detection circuit uses a photo coupler to detect voltage application to the brake and generates detection signals that alert the control device to any malfunctions before they can cause complete brake failure, enabling preventive action.

Inventive Principle:

Principle #10Preliminary action

2Device complexity

If relay or contact circuit is used for brake drive control, then the circuit structure is simple, but the circuit reaches end of service life quickly due to high frequency engagement/disengagement

Engineering Contradiction:

Improvecontrol circuit structureVSAvoidcircuit service life

Core Design Contradiction:

Device complexityVSDuration of action of stationary object

Solution Approach 1:

The patent replaces mechanical relay or contact circuit components with semiconductor switching devices (Tr1 and Tr2) that have no moving parts. This substitution eliminates wear and contact degradation issues inherent in mechanical systems, allowing the brake control circuit to withstand high frequency engagement/disengagement operations throughout the robot's operational lifetime.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If output short-circuit detection is not implemented, then the control circuit is simpler, but the brake may disengage during emergency stop creating safety hazards

Engineering Contradiction:

Improvedetection circuit complexityVSAvoidbrake disengagement during emergency stop

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The detection circuit continuously monitors the brake circuit status and provides feedback to the control device. When a malfunction such as output short-circuiting is detected, the detection signal is immediately transmitted to the control device, which can then take corrective action to maintain brake engagement during emergency stop conditions, preventing the harmful effect of unintended brake disengagement.

Inventive Principle:

Principle #23Feedback

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

Enables continuous monitoring and testing of brake drive control circuits during robot operation, enhancing safety and reliability by detecting malfunctions promptly and preventing brake failure, even during emergency stops.

Implementation Method 1

a voltage detection circuit which detects the presence of voltage which is applied to the brake is provided connected in parallel to the brake

Methodology Applied

Scientific EffectVoltage detection: Electric Field

Data Source

PatentUS9598064B2Brake drive control device provided with abnormality detection function

Publication Date: 2017.03.21 FANUC LTD

AI summary

A brake drive control circuit of a servo motor which detects malfunction of a semiconductor circuit at the brake drive control circuit, that is, a brake drive control circuit which connects two semiconductor circuits in series to a brake and uses a voltage detection circuit which detects the presence of voltage which is applied to the brake by brake signals turning the semiconductor circuits on/off so as to detect test pulses in the voltage which is applied to the brake due to test pulses which are included in the brake signals and turn the semiconductor circuits off for instants during an operation for disengaging the brake and detect malfunctions of the semiconductor circuits by the detection of the test pulses.