How to Make an All-direction Vehicle

7/24/2019 How to Make an All-direction Vehicle

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How to Make an All-direction Vehicle with Mecanum Wheels

The all-direction vehicle is equipped with four Mecanum wheels. The cool part of this

vehicle is the flexibility of moving in any direction while keeping itself in a constant

direction. It is achieved with the special structure of Mecanum wheel and their proper

configuration on the vehicle. You can visit thewebsitehttp://www.chiefdelphi.com/media/papers/1836and download the


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omndirectional.pdf file to get to know how it works. In general, the speeds of Mecanum

wheel are governed by the equations in the picture.

So, lets build a real one from assembling its framework.

Step 1: Assemble Rectangle Framework

Assemble rectangle framework with beams and screws from Makeblock

Step 2: Encoder Motors

The speed of four Mecanum wheel is dependent on the speed of vehicle, therefore, it

should be precisely controlled to avoid wheel sliding. Encoder motors are used toachieve this goal.


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Step 3: Install motors on the framework

Step 4: Install Mecanum wheels

Step 5: Wiring

An encoder motor driver from Makeblock is able to drive two encoder motors. Twoencoder motor drivers are enough for this vehicle. They are connected to port 1 and


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port 2 on the Orion board respectively. Please keep consistent between wiring and

defining ports in your codes.

Step 6: Install a battery

The framework of all-direction

vehicle with Mecanum wheels is shown in the figure above.

Step 7: Programming


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The speed of four Mecanum wheels are determined by the angular velocity and

speeds in x-axis and y-axis of the vehicle. A Joystick is used to control the speed of

the platform with left stick for, and right stick for.

Plug a Me USB Host module into port 3 of Orion board and then plug a wireless

module into Me USB Host module.

Step 8: Upload codes to Orion board and have fun

Upload codes with Arduino IDE, you are ready to play with this cool vehicle.

#include "Wire.h"

#include "SoftwareSerial.h"#include "MeOrion.h"

MeUSBHost joypad(PORT_3);

MeEncoderMotor motor1(0x02, SLOT2);

MeEncoderMotor motor2(0x02, SLOT1);

MeEncoderMotor motor3(0x0A, SLOT2);

MeEncoderMotor motor4(0x0A, SLOT1);

float linearSpeed = 100;

float angularSpeed = 100;

float maxLinearSpeed = 200;

float maxAngularSpeed = 200;

float minLinearSpeed = 30;

float minAngularSpeed = 30;

void setup()

{

motor1.begin();

motor2.begin();

motor3.begin();

motor4.begin();

Serial.begin(57600);

joypad.init(USB1_0);


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}

void loop()

{

Serial.println("loop:");

//setEachMotorSpeed(100, 50, 50, 100);

if(!joypad.device_online)

{

Serial.println("Device offline.");

joypad.probeDevice();

delay(1000);

}

else{

int len = joypad.host_recv();

parseJoystick(joypad.RECV_BUFFER);

delay(5);

}

//delay(500);

}

void setEachMotorSpeed(float speed1, float speed2, float speed3, float speed4)

{

motor1.runSpeed(speed1);

motor2.runSpeed(-speed2);



}

void parseJoystick(unsigned char *buf) //Analytic function, print 8 bytes from

USB Host

{

// debug joystick

// int i = 0;

// for(i = 0; i < 7; i++)

// {

// Serial.print(buf[i]);


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// Serial.print('-');

// }

// Serial.println(buf[7]);

// delay(10);

// increase and decrease speed

switch (buf[5])

{

case 1:

linearSpeed += 5;

if (linearSpeed > maxLinearSpeed)

{

linearSpeed = maxLinearSpeed;}

break;

case 2:

angularSpeed += 5;

if (angularSpeed > maxAngularSpeed)

{

angularSpeed = maxAngularSpeed;

}break;

case 4:

linearSpeed -= 5;

if (linearSpeed < minLinearSpeed)

{

linearSpeed = minLinearSpeed;

}

break;

case 8:

angularSpeed -= 5;

if (angularSpeed < minAngularSpeed)

{

angularSpeed = minAngularSpeed;

}

break;

default:

break;


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}

if ((128 != buf[0]) || (127 != buf[1]) || (128 != buf[2]) || (127 != buf[3]))

{

float x = ((float)(buf[2]) - 127) / 128;

float y = (127 - (float)(buf[3])) / 128;

float a = (127 - (float)(buf[0])) / 128;

mecanumRun(x * linearSpeed, y * linearSpeed, a * angularSpeed);

}

else

{switch (buf[4])

{

case 0:

mecanumRun(0, linearSpeed, 0);

break;

case 4:

mecanumRun(0, -linearSpeed, 0);

break;case 6:

mecanumRun(-linearSpeed, 0, 0);

break;

case 2:

mecanumRun(linearSpeed, 0, 0);

break;

case 7:

mecanumRun(-linearSpeed / 2, linearSpeed / 2, 0);

break;

case 5:

mecanumRun(-linearSpeed / 2, -linearSpeed / 2, 0);

break;

case 1:

mecanumRun(linearSpeed / 2, linearSpeed / 2, 0);

break;

case 3:

mecanumRun(linearSpeed / 2, -linearSpeed / 2, 0);


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break;

default:

mecanumRun(0, 0, 0);

break;

}

}

}

void mecanumRun(float xSpeed, float ySpeed, float aSpeed)

{

float speed1 = ySpeed - xSpeed + aSpeed;

float speed2 = ySpeed + xSpeed - aSpeed;

float speed3 = ySpeed - xSpeed - aSpeed;float speed4 = ySpeed + xSpeed + aSpeed;

float max = speed1;

if (max < speed2) max = speed2;



if (max > maxLinearSpeed){

speed1 = speed1 / max * maxLinearSpeed;




}

setEachMotorSpeed(speed1, speed2, speed3, speed4);

}

How to Make an All-direction Vehicle

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