Dual-channel safety torque turn-off circuit and dual-channel safety torque turn-off method

Abstract

The invention discloses a dual-channel safety torque turn-off circuit and a dual-channel safety torque turn-off method. The circuit comprises a dual-channel STO input module, a power switch module, anMCU control module and an isolation driving module. The power switch module is connected with the dual-channel STO input module and the isolation driving module, and the MCU control module is connected with the dual-channel STO input module and the isolation driving module. The dual-channel STO input module receives an external STO signal, and outputs a standard STO signal to the power switch module through isolation and filtering; the power switch module triggers the power supply voltage to the isolation driving module according to the STO signal, and the MCU control module controls the PWMsignal to be output to the isolation driving module; and the isolation driving module drives the external motor according to the power supply voltage and the PWM signal. According to the scheme, powersupply control is carried out on the isolation driving module from a circuit level, the safe and reliable operation of an STO function is guaranteed, and through the hardware judgment and software judgment on STO signals, it is effectively guaranteed that accidental torque does not occur.

Description

technical field [0001] The invention relates to the technical field of circuits, in particular to a dual-channel safe torque off circuit and method. Background technique [0002] In recent years, motor drives have been widely used in CNC machine tools, production line control, robot industries, etc., among which the safety of mechanical control has always been paid attention to. Safe Torque Off (STO) is a safety function of the inverter and the servo drive. This function is used to disconnect the output torque. At this time, the motor loses power and cannot output torque, so it cannot start. The Safe Torque Off function is often used for emergency stops, mechanical maintenance, safety interlocks, or in other combinations of safety functions. [0003] The current STO function circuit mostly uses dual redundant design, the control circuit is composed of safety relay, feedback loop and indication loop, etc., the circuit components are composed of many components and the struct...

AI Technical Summary

Problems solved by technology

[0003]The current STO function circuit mostly uses dual-circuit redundant design, and the control circuit is composed of safety relay, feedback loop and indication loop, etc., with many circuit components and complex structure

However, even with a dual redundant STO design, it is difficult to guarantee that the protection failure due to fault accumulation will not occur during continuous operation. At the same time, errors in the drive will also trigger STO and cause protection failure.

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