I. Motion Controller
First, let's learn about motion controllers.
The application of motion control in the fields of robotics and CNC machine tools is more complex than its application in specialized machines, because the latter have simpler motion patterns and are often referred to as general motion control (GMC).
A motion controller generates a feedback loop for the trajectory point (desired output) and closed position. Many controllers can also internally close a velocity loop. A driver or amplifier converts the motion controller's control signal (typically a speed or torque signal) into a higher-power current or voltage signal. More advanced intelligent drives can close both the position and velocity loops themselves for more precise control.
Advantages: (1) The hardware composition is simple. The system can be formed by inserting the motion controller into the PC bus and connecting the signal lines; (2) The rich software already available on the PC can be used for development; (3) The code of the motion control software has good universality and portability; (4) There are many engineers who can carry out development work, and development can be carried out without much training.
Disadvantages: (1) The motion controller with board structure uses gold finger connection and is fixed on one side. In most industrial sites with poor environment (serious vibration, dust, and oil pollution), it is not suitable for long-term operation. (2) Waste of PC resources. Due to the bundled sale of PCs, users actually only use a small portion of the PC resources. The unused PC resources not only cause idleness and waste, but also bring maintenance troubles. (3) Overall reliability is difficult to guarantee. Since the PC can be an industrial computer or a commercial computer, the reliability after system integration is very different and cannot be guaranteed by the motion controller. (4) It is difficult to highlight industry characteristics.
As mechanical manufacturing OEMs become increasingly familiar with motion controller products, motion controllers have been expanding their application areas and scope, achieving breakthroughs in some non-traditional niche industries. Although these industries only account for a small portion of the motion controller market, these areas are poised to become future profit growth drivers and provide market opportunities for many small and medium-sized companies. Examples include wind turbine pitch control systems, oilfield pumping units, flame cutting machines, silicon wafer cutting machines, solar tracking systems, spring machines, and flocking machines.
II. How to resolve motion controller failures
In this section, we will mainly discuss the scenarios in which motion controllers fail.
In terms of the form of expression, there are several possibilities:
1. Damage to power devices. 2. Damage to the internal power supply of the controller. 3. Intermittent operation of the controller. 4. Loss of control signals due to worn connecting wires, poor contact of connectors, or detached connectors.
Analysis of the causes of the above failure modes:
A. Several possible causes of damage to power devices: motor damage, poor quality of the power device itself or selection of an insufficient grade, loose device installation or vibration, motor overload, damage to the power device drive circuit or unreasonable parameter design.
B. Several possible causes of damage to the internal power supply of the controller: short circuit in the internal circuit of the controller, short circuit in the peripheral control components, and short circuit in the external leads.
C. Several possible reasons for intermittent operation of the controller: parameter drift of the device itself in high or low temperature environment, high power consumption of the overall controller design causing some devices to overheat and enter the protection state, and poor contact.
D. The following are some possible causes of wear and tear on the connecting wires and poor or detached contact of the connectors: improper selection of wires, inadequate protection of the wires, poor selection of connectors, and loose crimping between the wire harness and the connector.
