Multiaxial Motor Control System Emergency Braking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional multiaxial motor control systems require a long braking distance and apply significant stress to loads during emergency stops, as they disconnect electrification immediately, leading to safety issues and prolonged stopping times due to the need for synchronization between shafts.
Innovation Solution
The system includes motor control devices with a communication controller, rotation controller, and drive unit that apply braking torque even during communication failures, allowing for immediate stopping of motors while maintaining electrification, thereby reducing stopping distance and stress on loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the conventional system disconnects electrification immediately during emergency stop, then the motor stops, but the braking distance becomes long and significant stress is applied to loads
Solution Approach 1:
The motor control device preliminarily determines whether to apply braking torque by evaluating communication failure conditions before the emergency stop is fully executed. This preliminary determination allows the system to prepare braking action in advance, reducing the overall braking distance while maintaining safety.
Solution Approach 2:
The system changes the operational parameter of the motor from free coasting (when electrification is disconnected) to active braking (when braking torque is applied). By controlling the torque parameter dynamically based on communication status, the system achieves shorter braking distance without compromising safety.
2Reliability
If the conventional system disconnects electrification immediately during emergency stop, then the motor stops, but significant stress is applied to loads
Solution Approach 1:
The motor control device preliminarily determines the appropriateness of applying braking torque by evaluating communication failure conditions before the emergency stop is fully executed. This preliminary assessment allows the system to choose a gentler stopping method when appropriate, reducing stress on loads while maintaining safety.
Solution Approach 2:
The system dynamically changes the torque parameter from maximum braking torque to reduced or zero torque based on communication status and load conditions. This parameter adjustment allows the system to achieve safety without applying excessive stress to the loads.
3Length of moving object
If the system applies braking torque during communication failures, then the stopping distance is reduced, but the device complexity increases
Solution Approach 1:
The motor control device autonomously determines whether to apply braking torque by monitoring communication status itself, without requiring external control signals. This self-service capability reduces the need for additional control infrastructure while achieving shorter braking distances.
Solution Approach 2:
The system uses feedback from the communication controller about communication failure status to automatically adjust the braking torque application. This feedback mechanism enables the system to respond appropriately to communication issues without increasing overall device complexity.
4Length of moving object
If the system maintains electrification during emergency stop to reduce braking distance, then the stopping is faster, but energy consumption increases
Solution Approach 1:
The system dynamically changes the torque parameter from maximum braking torque to reduced or zero torque based on communication status and load conditions. This parameter adjustment allows the system to achieve safety without applying excessive stress to the loads.
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
The solution enables motors to stop quickly and safely in a shorter braking distance, reducing stress on loads and improving safety by applying braking torque during communication failures, while maintaining motor electrification.
Implementation Method 1
When at least one of the motor control devices detects failure in reception of the command signal, the at least one of the motor control devices outputs a torque command for braking torque to stop the corresponding one of the motors
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The invention provides a multiaxial motor control system configured to control motors for a plurality of shafts included in a multiaxial machine, and including a plurality of motor control devices and a controller. The controller has network connection with the motor control devices, and is configured to transmit a command signal to the motor control devices. Each of the motor control devices includes a communication controller, a rotation controller, and a drive unit, and is configured to drive a motor for a corresponding one of the shafts. The communication controller is configured to transmit and receive signals including the command signal, and determine whether or not the command signal is received normally. The rotation controller is configured to generate a torque command for operation of the corresponding one of the motors. The drive unit is configured to generate a drive voltage for electrification to drive the corresponding one of the motors in accordance with the torque command. When at least one of the motor control devices detects failure in reception, the at least one of the motor control devices outputs a torque command for braking torque to stop the corresponding one of the motors.