Teleoperation Robot

The Teleoperation Robot is a differential drive robotic system that allows remote control via a keyboard interface. This project provides a Python-based teleoperation system, enabling users to control the robot’s movement in real-time. The robot is equipped with two independent motors and utilizes a PID controller for smooth and precise motion control.

About Tools and Materials:

2x SMD Red (Purchase Here)

SMD USB Gateway (Purchase Here)

Arduino Gateway Module (Purchase Here)

2x BDC Motor (Purchase Here)

Step 1: Hardware & Software Overview

Project Key Components

1. SMD

   The SMD acts as a bridge between the script and the modules. It is responsible for interpreting the commands sent by the script and translating them into actions that read input from the Ultrasonic Distance Sensor Module and meanwhile, actuate the motor for the continuous reading of the script.

2. BDC Motor

   The 100 RPM BDC Motor with Encoder is used to rotate the radar mechanism in a full circle. The user can precisely control the motor and get the position through the built-in encoder.

Key Features:

• Real-time teleoperation via keyboard inputs.

• PID-based motor control for smooth and stable movement.

• Cross-platform support (Windows, Linux, macOS).

• USB serial communication for motor control.

• Differential drive mechanism for precise navigation.

• Emergency stop function to halt movement immediately.

Step 2: Assemble

1. Hardware Setup

   • Connect the SMD to the PC or Arduino board using USB Gateway Module or Arduino Gateway Module.

   • Connect the 100 RPM BDC Motor with Encoder to the motor ports of the SMD using an RJ-45 cable.

   • Make sure that the SMD is powered and all connections are correct.

Project Wiring diagram

Step 3: Run & Test

Codes

from pynput import keyboard
import time
from smd.red import *
from serial.tools.list_ports import comports
from platform import system

class PIDController:

    def __init__(self, kp, ki, kd):
        self.kp = kp
        self.ki = ki
        self.kd = kd
        self.previous_error = 0
        self.integral = 0

    def calculate(self, error, delta_time):
        self.integral += error * delta_time
        derivative = (error - self.previous_error) / delta_time if delta_time > 0 else 0
        output = (self.kp * error) + (self.ki * self.integral) + (self.kd * derivative)
        self.previous_error = error
        return max(min(output, 100), -100)  
    
    def USB_Port():
        ports = list(comports())
        usb_names = {
            "Windows": ["USB Serial Port"],
            "Linux": ["/dev/ttyUSB"],
            "Darwin": [
                "/dev/tty.usbserial",
                "/dev/tty.usbmodem",
                "/dev/tty.SLAB_USBtoUART",
                "/dev/tty.wchusbserial",
                "/dev/cu.usbserial",
            ]
        }
        os_name = system()
        if ports:
            for port, desc, hwid in sorted(ports):
                if any(name in port or name in desc for name in usb_names.get(os_name, [])):
                    print("Connected!")
                    return port
            print("Available ports:")
            for port, desc, hwid in ports:
                print(f"Port: {port}, Description: {desc}, HWID: {hwid}")
        else:
            print("No ports detected!")
        return None
    
    def teleoperate_smd():
        print("Use W/A/S/D to control the robot. Press Q to quit.")
    
        port = USB_Port()
        if not port:
            print("No suitable port found. Exiting...")
            return
    
        try:
            smd = Master(port)
            smd.attach(Red(0))  # Left motor (ID 0)
            smd.attach(Red(1))  # Right motor (ID 1)
            
            smd.enable_torque(0, 1)
            smd.enable_torque(1, 1)
    
            left_pid = PIDController(kp=24.96, ki=0.00, kd=19.10)
            right_pid = PIDController(kp=46.97, ki=0.00, kd=18.96)
    
            base_speed = 100  
            turning_speed = 100  # Speed for turning
            last_time = time.time()
    
            def on_press(key):
                nonlocal last_time
    
                try:
                    # Calculate time difference
                    current_time = time.time()
                    delta_time = current_time - last_time
                    last_time = current_time
    
                    if hasattr(key, 'char'):
                        if key.char == 'w':  # Move forward
                            print("Move Forward")
                            error = base_speed
                            left_speed = left_pid.calculate(error, delta_time)
                            right_speed = right_pid.calculate(error, delta_time)
                            # Send commands to both motors simultaneously
                            smd.set_duty_cycle(0, -left_speed)  # Left motor forward
                            smd.set_duty_cycle(1, right_speed)  # Right motor forward
                        elif key.char == 's':  # Move backward
                            print("Move Backward")
                            error = -base_speed
                            left_speed = left_pid.calculate(error, delta_time)
                            right_speed = right_pid.calculate(error, delta_time)
                            # Send commands to both motors simultaneously
                            smd.set_duty_cycle(0, -left_speed)  # Left motor backward
                            smd.set_duty_cycle(1, right_speed)  # Right motor backward
                        elif key.char == 'a':  # Turn left
                            print("Turn Left")
                            # Send commands to both motors simultaneously
                            smd.set_duty_cycle(0, 0)  # Left motor stopped
                            smd.set_duty_cycle(1, turning_speed)  # Right motor forward
                        elif key.char == 'd':  # Turn right
                            print("Turn Right")
                            # Send commands to both motors simultaneously
                            smd.set_duty_cycle(0, -turning_speed)  # Left motor forward
                            smd.set_duty_cycle(1, 0)  # Right motor stopped
                        elif key.char == 'q':  # Quit
                            print("Exiting...")
                            return False
                except AttributeError:
                    pass

        def on_release(key):
            # Stop both motors simultaneously
            smd.set_duty_cycle(0, 0)
            smd.set_duty_cycle(1, 0)

        # Start keyboard listener
        with keyboard.Listener(on_press=on_press, on_release=on_release) as listener:
            listener.join()

    except Exception as e:
        print(f"Error: {e}")
    finally:
        # Stop both motors simultaneously during cleanup
        smd.set_duty_cycle(0, 0)
        smd.set_duty_cycle(1, 0)
        smd.enable_torque(0, 0)
        smd.enable_torque(1, 0)
        smd.close()
        print("SMD connection closed.")

teleoperate_smd()