Distance Auto Stop

This project showcases a dynamic motor control system utilizing the ACROME SMD platform. The project integrates hardware, real-time processing, and dynamic scaling to achieve precision control. The goal is to create a motorized system where the speed decreases as the motor approaches an object and stops completely when it gets very close. This is achieved using distance measurements and velocity interpolation.

Key Features

1. Distance-Based Motor Control The motor dynamically adjusts its speed based on proximity.

2. Smooth Interpolation The velocity decreases gradually instead of abrupt stops, ensuring smoother operation.

3. Real-Time Feedback The system logs current distance and velocity values for monitoring.

Hardware Components

1. ACROME SMD Red Platform The ACROME SMD platform serves as the control hub, interfacing with the motor and reading sensor data.

2. Ultrasonic Distance Sensor A distance sensor is used to measure the object's position in real-time.

3. Motor The motor is controlled using velocity commands, allowing for smooth acceleration and deceleration.

Getting Started

1. Hardware Setup

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

   • Connect the Ultrasonic Distance Sensor to the SMD using an RJ-45 cable.

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

2. Run the Script

   • Run the script on your computer. This will establish communication with the SMD and initiate control of the Ultrasonic Distance Sensor.

Python Code

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

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",
            		"/dev/cu.usbmodem",
			"/dev/cu.SLAB_USBtoUART",
			"/dev/cu.wchusbserial",
		]
	}
	
	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, [])):
				return port
		print("Current ports:")
		for port, desc, hwid in ports:
			print(f"Port: {port}, Description: {desc}, Hardware ID: {hwid}")
	else:
		print("No port found")
	return None
	
port = USB_Port()
if port is None:
    print("No suitable USB port found.")
    exit(1)

m = Master(port)
m.attach(Red(0))

middle_distance = 20
near_distance = 5
max_speed = 100
m.set_shaft_cpr(0,6533)
m.set_shaft_rpm(0,100)
m.enable_torque(0,1)

while True:
    distance = m.get_distance(0,1)

    if distance < near_distance:
        m.set_duty_cycle(0, 0)
        print("Stopped")
    elif near_distance <= distance < middle_distance:
        speed = max_speed * (distance - near_distance) / (middle_distance - near_distance)
        speed = max(10, speed)
        m.set_duty_cycle(0, speed)
        print("Running at speed:", speed)
    else:
        m.set_duty_cycle(0, max_speed)
        print("Running at max speed")

Arduino Code

#include <Acrome-SMD.h>
#define ID         0 
#define CPR        6533   
#define BAUDRATE   115200 

Red master(ID, Serial, BAUDRATE); 

void setup() {
  master.begin();
  master.torqueEnable(1);       
  Serial.begin(115200); 
}

void loop() {
  int distance = master.getDistance(1);
  Serial.print("Distance: ");
  Serial.println(distance);

  // Define velocity scaling parameters
  int maxVelocity = 1000;  // Maximum velocity 
  int minVelocity = 0;     // Minimum velocity
  int stopDistance = 20;   // Distance at which motor should start slowing down
  int fullStopDistance = 5; // Distance at which motor completely stops

  // Check if motor needs to slow down or stop
  int velocity;
  if (distance > stopDistance) {
    // Full speed if distance is greater than stop threshold
    velocity = maxVelocity;
  } else if (distance > fullStopDistance) {
    // Gradually reduce velocity as distance decreases
    velocity = map(distance, fullStopDistance, stopDistance, 0, maxVelocity);
  } else {
    // Completely stop the motor when very close
    velocity = 0;
  }

  // Set motor to velocity mode and set velocity
  master.setOperationMode(2);
  master.setpoint(2, velocity);

  // Small delay to prevent overwhelming the system
  delay(50);
}

Conclusion

This project highlights the ACROME SMD Red platform's versatility in creating advanced motor control systems. By combining real-time distance sensing with velocity interpolation, it provides a robust solution for a range of applications.