Linear Actuator
What is Linear Actuator?
A linear actuator is a device in which the position of the device changes linearly. The displacement happens linear which is controlled by angular rotation.There is a wide application of linear actuator where one wants to move something but they do not want to physically get involved in moving it. There are quite a number of ways to control linear actuators depending on the application and the user experience required. These are the key aspects determining the setup and the way this setup will operate. It is common for most movements to involve manual control using remote control or a rocker switch. It is however paramount, that the system has some form of intelligence to improve the level of efficiency involved.
How to construct it:
Collect the apparatus:
- MOTOR (Stepper motor is preferred. By using this we can do very small linear displacement, which will be controlled by the angular displacement of the motor).
- SCREW shape ROD (Big size is preferred for long linear displacement).
- SCREW LEG.
- HOLLOW PIPE.
- RIGHT ANGLE shape small Metal Sheet.
- POWER SUPPLY (to rotate the motor).
- HOLLOW PIPE with small diameter (Shape is should be attach with motor shaft).
- If you have a screw shape rod then attach it to the motor.If you have not then cut the nut head, it will be turned in a rod. Now connect it to the motor shaft with the small size of pipe.
- Fix the motor with a clamp to somewhere.
- Cut the hollow pipe 2 side like this
- Attach the RIGHT ANGLE shape clamp with each side of the screw leg by welding.
- Insert this screw leg including screw shape rod inside the hollow pipe and way out the right angle side of the clamp from the hollow side of the pipe to prevent the screw leg’s rotation. Because it’ll do the linear displacement.
- Now attach the cut hollow pipe with a clamp to somewhere including motor.
Controlling Linear Actuator using Arduino
Microcontrollers, and relays in some cases are required for the intelligence in the system setup. Here we use an Arduino, a popular microcontroller board that provides an ease of setting up. There are other alternatives, but Arduino has a lower learning curve.
The parts required for the project setup are Arduino UNO, progressive automation PA-14-6-50, 12V 5A power supply, female power plug, small flat head screwdriver, pololu VNH5019 motor driver rated at 12v5a and SPDT relays. These are easily available, and are part of a setup that is easy to build and comes up with a powerful automated system.
Actuator
In reference to the linear actuator circuit assembly, the board comes with male headers and screw terminals unattached. This can be attached through a soldering iron. There are four holes on the board which are considerably large. These are for the wires which are not the right spacing, considering the screw terminals. However, there are a pair of smaller holes which are the right fit.. The female power plug is then screwed onto the GND/VIN on the VNH5019. This allows easy plugging and unplugging the power supply. It is also possible to put switch to facilitate for an E-stop.
Arduino is powered via a USB. It is also possible to have a 12v5a power as well as the USB. It is important to note that the Arduino can handle 12V power, so one can get the 12v6a power supply and still power everything using the USB.
Software
There is software required to automate the functions of the setup. The first part includes making sure that the Arduino pins that trigger the relays are set to outputs.
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//Use constants for the relay pins in case you need to change these later
const int relay1 = 6; //Arduino pin that triggers relay #1
const int relay2 = 7; //Arduino pin that triggers relay #2
void setup() {
//Set pinMode to OUTPUT for the two relay pins
pinMode(relay1, OUTPUT);
pinMode(relay2, OUTPUT);
}
void extendActuator() {
digitalWrite(relay1, HIGH);
digitalWrite(relay2, LOW);
}
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It is crucial to test if the setup is working. In the code below, the actuator is set to extend for one second, stop for one second, retract for one second and the pause for five seconds, before repeating the process.
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void retractActuator() {
digitalWrite(relay1, LOW);
digitalWrite(relay2, HIGH);
}
void stopActuator() {
digitalWrite(relay1, LOW);
digitalWrite(relay2, LOW);
void loop() {
extendActuator();
delay(1000);
stopActuator();
delay(1000);
retractActuator();
delay(1000);
stopActuator();
delay(5000);
/Use constants for the relay pins in case you need to change these later
const int relay1 = 7; //Arduino pin that triggers relay #1
const int relay2 = 6; //Arduino pin that triggers relay #2
.
Application:
- Modern life is the era of Automation. So by using this we can make a automotive device whose working is happened by linear displacement
- Linear actuators produce push/pull action. Rotary actuators produce rotational motion.
- Actuators are used extensively to operate valves remotely
- Actuators are also used in many linear motion applications where air power is not available to drive cylinders or where extra force is needed from compact designs.
Reference:
https://www.instructables.com/id/Control-a-Large-Linear-Actuator-With-Arduino/
https://www.theengineeringprojects.com/2017/11/how-to-use-an-arduino-with-linear-actuators.html
https://www.electronicsforu.com/electronics-projects/controlling-linear-actuator-arduino