Motor Control Device Emergency Stop Circuit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional motor control devices with emergency stop functions face safety issues due to reliance on complex software processes and single shut-off mechanisms, leading to potential motor malfunction and delayed response in emergency situations.
Innovation Solution
A motor control device with multiple input ports for emergency stop signals, utilizing PWM signals and separate drive circuits for P-side and N-side power switching devices to ensure reliable and rapid motor shutdown through independent shut-off functions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single shut-off function is used to stop the motor, then the device complexity is reduced, but the reliability of the emergency stop function deteriorates because the shut-off function itself may break down
Solution Approach 1:
The patent divides the single shut-off function into multiple independent shut-off functions (first and second shut-off functions). Each function operates independently to stop the motor through different pathways, ensuring that if one function fails, the other can still perform the emergency stop. This segmentation increases reliability without requiring a single complex redundant system.
Solution Approach 2:
The patent applies different characteristics to different parts of the shut-off system. The first shut-off function stops the PWM signal generation, while the second shut-off function stops the gate drive signal generation. Each part has a specialized local function, allowing independent failure modes and improving overall system reliability through functional differentiation.
2Speed
If complex software processes are used to process emergency stop signals through CPUs, then the adaptability of the control system is improved, but the response speed deteriorates due to time intervals determined by software programs
Solution Approach 1:
The patent extracts the emergency stop signal processing from the complex software CPU routines and implements it through dedicated hardware circuits. The first and second emergency stop signals are processed by separate hardware pathways that directly control the shut-off functions without software intervention, achieving immediate response speed while removing software-related delays and complexity.
Solution Approach 2:
The patent replaces the software-based emergency stop processing mechanism with a hardware-based mechanism. Instead of using CPU software programs to process emergency stop signals, the system uses dedicated hardware circuits that respond instantaneously to emergency stop inputs, substituting the mechanical/software process with a faster hardware response system.
3Reliability
If two emergency stop signals are inputted to CPUs for consistency checking, then the reliability of signal verification is improved, but the device complexity increases due to the need for multiple circuits and software processing
Solution Approach 1:
The patent merges the functions of multiple emergency stop signal processing pathways into a unified hardware architecture. Both the first and second emergency stop signals are processed through dedicated hardware circuits that converge on the same motor shut-off mechanisms, combining verification reliability with streamlined circuit design rather than requiring separate complex processing systems.
Data Source
Figure 1
Figure 2
AI summary
A motor control device, which receives at least two emergency stop signals, includes an LSI, a PWM signal transmission circuit, a drive circuit, and an inverter circuit. The LSI generates PWM signals. The PWM signal transmission circuit transmits the PWM signals. The drive circuit generates inverter drive signals. The inverter circuit includes a P-side power switching device and an N-side power switching device. The drive circuit includes a P-side drive circuit for driving the P-side power switching device, and an N-side drive circuit for driving the N-side power switching device. One of the emergency stop signals is inputted to the P-side drive circuit and the PWM signal transmission circuit. The other emergency stop signal is inputted to the N-side drive circuit and the PWM signal transmission circuit. In response to the receipt of an emergency stop signal, the PWM signal transmission circuit stops transmitting the PWM signals, and the drive circuit stops outputting the inverter drive signals.