# 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](https://docs.acrome.net/electronics/smd-red) ([Purchase Here](https://www.robotshop.com/products/acrome-smd-red-smart-brushed-motor-driver-with-speed-position-and-current-control-modes))
[SMD USB Gateway](https://docs.acrome.net/electronics/gateway-modules/usb-gateway-module) ([Purchase Here](https://www.robotshop.com/products/acrome-usb-gateway-module-acrome-smd-products))
[Arduino Gateway Module](https://docs.acrome.net/electronics/gateway-modules/arduino-gateway-module) ([Purchase Here](https://www.robotshop.com/products/acrome-arduino-gateway-shield-module-acrome-smd-products))
2x [BDC Motor](https://docs.acrome.net/electronics/electrical-motors/brushed-dc-motors-bdc) ([Purchase Here](https://www.robotshop.com/products/acrome-12v-brushed-dc-motor-with-built-in-encoder-100-rpm-speed))
## **Step 1: Hardware & Software Overview**
#### **Project Key Components**
1. [**SMD**](https://docs.acrome.net/electronics/smd-red)
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](https://acrome.gitbook.io/acrome-smd-docs/electronics/add-on-modules/ultrasonic-distance-sensor-module) and meanwhile, actuate the motor for the continuous reading of the script.
2. [BDC Motor](https://docs.acrome.net/electronics/electrical-motors/brushed-dc-motors-bdc)
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](https://acrome.gitbook.io/acrome-smd-docs/electronics/gateway-modules/usb-gateway-module) or [Arduino Gateway Module](https://acrome.gitbook.io/acrome-smd-docs/electronics/gateway-modules/arduino-gateway-module).
* Connect the 100 RPM [BDC Motor](https://docs.acrome.net/electronics/electrical-motors/brushed-dc-motors-bdc) 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
**1. Connect the Robot**\
• Ensure that the robot is powered on and all connections are secure.\
• The USB connection should be properly established before running the script.
**2. Run the Teleoperation Script**\
• Open a terminal or command prompt.\
• Navigate to the directory where the script is located.\
•Run the Code.
**3. Control the Robot**\
Once the script is running, use the following keyboard controls to operate the robot:\
\
**Key Action:**\
W: Move forward\
S: Move backward\
A: Turn left\
D: Turn right\
Q: Quit the program\
\
• The script initializes a PID controller for both motors to ensure smooth operation.\
• It automatically detects the correct USB port for communication with the SMD module.
**4. Verify Motion and Response**\
• When pressing the movement keys, observe the robot’s response.\
• Check if the movements are smooth and consistent.\
• If any delays or unexpected behaviors occur, review the USB connection and the PID parameters.
**5. Check for Errors**\
• If the script fails to detect the USB port, it will display No suitable port found. Exiting...\
• Any communication or motor control issues will be printed as error messages in the terminal.
**6. Stopping and Exiting**\
• When pressing Q, the script will stop the motors and disable torque before exiting safely.\
• If the robot does not stop as expected, manually disconnect the power or reset the system.
## **Codes**
{% code lineNumbers="true" %}
```python
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()
```
{% endcode %}
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