Motor Actuator Control System Based on AVR Single Chip Microcomputer

Introduction: The motor actuator control system is a controller specially used to control the air volume of the cement plant ventilation duct. The CPU adopts the AVR single-chip microcomputer series ATMEGA16L. This control system directly drives a motor actuator, and the actuator drives a movable louver. By adjusting the rotation angle of the movable louver, the air volume passing through the ventilation duct can be controlled.

The motor actuator control system is a controller specially used to control the air volume of the cement plant ventilation duct. The CPU adopts the AVR single-chip microcomputer series ATMEGA16L. This control system directly drives a motor actuator, and the actuator drives a movable louver. By adjusting the rotation angle of the movable louver, the air volume passing through the ventilation duct can be controlled.

The motor actuator control system is shown in Figure 1. The control system input signals include the following groups.

1. Two sets of 4-20mA current signals.

2.4 switch signals.

3. Two sets of 0-5V analog voltage signals.

4.4 key input control.

5.220V AC direct input.

6. The controller output signals are as follows:

7. A set of 4-20mA current signal.

8.5 groups of relay normally open and normally closed points.

9. A set of 5V1A DC power supply.

10. A set of 24V.5A DC power supply.

11.3-digit digital tube display status.

Figure 1: AVR microcontroller-based motor actuator control system

The working process is described as follows:

The central control uses a set of 4-20mA signals to remotely control the ventilation volume. The controller collects the 4-20mA signals sent by the central control in real time to control the electric actuator in real time. The maximum angle of the blinds is 90 degrees, when the air outlet is fully open, and the minimum angle is 0 degrees, when the air outlet is fully closed. The controller corresponds the 4-20mA signal to 0-90 degrees to achieve control of the blinds. There is a 1K potentiometer on the central rotation axis of the blinds. The moving point of the potentiometer outputs an analog voltage signal. When the blinds rotate, the potentiometer moving point tap rotates with it. At this time, the moving point voltage changes in real time. The CPU can feedback the angle position of the blinds by collecting this analog voltage signal in real time, and then compare it with the central control signal to complete the control function. During the control process, the controller will also output a 4-20mA signal to the central control in real time to let the central control know the current angle position of the blinds.

There are several points to note during the control process:

1. In order to prevent the deviation between the central control 4-20mA signal and the rotation angle of the louver, the controller has the functions of zero adjustment and full adjustment, that is, when the central control signal is 5mA or other numbers, the controller can record this value as the 0-degree position of the louver, and when the central control signal is 18mA or other numbers, the controller can record this value as the 90-degree position of the louver.

2. When the electric actuator is rotating, the product accidentally causes the motor to get stuck. At this time, the over-torque signal connected to the motor will output a high level. When the controller detects this signal, it will immediately stop control to prevent damage to the motor.

3. When the motor rotates to the extreme positions at both ends, the open limit and close limit signals will be triggered respectively. When the controller detects these two signals, it will immediately stop control to prevent damage to the motor.

other instructions:

This controller does not use up all resources in this product application. Only two of the five relays are used to control the forward and reverse rotation of the motor, and the other three are available for backup. In addition, the analog voltage input and switch input are also available for backup.