•

Rounak Chowdhury

•

Kush Patel

Created December 15, 2021

ME461 Floor Mapping Robot Project

This is an obstacle detecting robot that can map itself and its surroundings in LabVIEW in real-time.

IntermediateWork in progress15 hours16

Things used in this project

Hardware components

Texas Instruments LAUNCHXL-F28379D C2000 Delfino LaunchPad

Raspberry Pi Orange Pi Lite

Digilent IR Range Sensor

Ultrasonic Sensor - HC-SR04 (Generic)

Geared DC Motor, 12 V

SparkFun RedBot Sensor - Wheel Encoder

Li-Polymer Battery, 150mAh

Software apps and online services

Texas Instruments Code Composer Studio

LabVIEW Community Edition

Hand tools and fabrication machines

Multitool, Screwdriver

Soldering iron (generic)

LulzBot TAZ 6

Story

Final Project Goals

The final project from ME 461 (UIUC) entails that we use the F28379D board, which we have been using for the past few weeks, to create an original project with our lab team members which can complete some tasks. Since our group has three members, our project will be slightly larger to accommodate the extra brainpower. The final project idea we had will have several features. Our robot will be able to drive around the field and detect obstacles. This robot will identify and avoid said obstacles while mapping its surroundings in LabVIEW. This map should be able to display the obstacles the robot detects.

The first part of the project will be rudimentary object avoidance, wall following, and accurate positioning. Through a combination of IR and ultrasonic, we want to be able to determine if there is an obstacle in the desired path of the robot and have some form of avoidance procedure to quickly adjust the path of the robot. We also want to be able to map out the space but for this, we need a relatively accurate manner of determining position. By using IR and the ultrasonic sensor we can determine a manner of detecting the distance from some number of walls and using trigonometry to determine the position in addition to the use of the motor encoders used in Lab 6. If there is drift or some issue in figuring out the position, some method of recalibrating through wall following will be added to avoid long-term drift.

The second part of this project will utilize LabVIEW to track the location of the robot on a LabVIEW-generated grid. LabVIEW will be connected via Wi-Fi to the robot so the robot can wirelessly send its position and bearing information to LabVIEW for plotting. This portion of the project will require LabVIEW2D picture code as well as TCP/IP code blocks to be able to receive data from C. I would like to take the bearing and position coordinates generated by the robot as it moves around and convert them into a tracked position on a LabVIEW grid. If possible, I would like to take the data from the obstacle detection portion of our code to plot these obstacles in LabVIEW to create a map of the environment, but the focus will be on the robot coordinates to create a pathing that the robot is taking.

Development

Sensor Integration

Two different types of sensors were selected for this project, 3 IR sensors, and 2 ultrasonics. The 3 IR sensors were located at the front of the robot (near the wheels). One IR sensor was based in the middle while the other two were on either side of the middle sensor with a 45-degree rotation. At the rear of the robot, the ultrasonics were placed on either side facing outwards.

For the initial obstacle detection and marking, IR sensors were used. We added an offset to these sensors, so when the robot moved next to an obstacle, they could be detected and their distances marked. The ultrasonics were used as a check during the avoiding phase of the motion. Since the robot pivots about the front wheel, the robot can risk hitting its rear on an obstacle. Because of this, ultrasonics are used as a check to make sure the whole robot has cleared the obstacle before attempting to turn back.

The IR sensors provide a voltage level as the signal so the ADC is used to translate the voltage to a 12-bit value. This 12-bit value is then brought back into voltage in the C code and the voltage is converted to a distance reading. The ultrasonic sensors work using the eCap functionality of the launchpad. An ultrasonic works by providing timing of when the sound is sent and bounces back to the sensor. This time difference can then be converted to a distance value.

Obstacle Avoidance and Pathing

Since the overall goal was to create a robot that can map out an area and the obstacles within it, a path needed to be used. For simplicity's sake, a path that simply goes up and down was used based on the geometries of the area of operation. However, as the robot reaches an obstacle it needs to maneuver around, the robot would essentially pivot until it reached an angle that would allow it to move straight without hitting the obstacle. Once the robot would fully clear the obstacle it would pivot back and move to maintain its path to continue mapping out the environment.

Wireless Data Transmission

Another major part of the project involved the transmission of data to LabView. The Orange Pi was chosen as our secondary board, for its WIFI capability, and for us to get some experience working with it for personal development. The Orange Pi was set up to receive values from the Redboard over UART. Then the Orange Pi would transmit this data over WIFI to LabVIEW using code ran on both the Orange Pi (TCPIP code) and Code Composer. The values that were transmitted included Robot (X, Y) coordinates, Robot Bearing angle, and Obstacle (X, Y) coordinates. Obstacles were detected and identified by the IR sensors to map them out. The FinalProject C file includes the data that was transmitted. The LabVIEW file then processed this data.

To allow a quick setup of the robot during demos, the FinalProject c file was flashed onto the robot, and the TCPIP C file was transferred to the Orange Pi. The Orange Pi used was the Orange Pi Lite, with the Armbian framework.

Labview

1 / 7 • Final Labview Image of entire VI

In LabVIEW, we needed to solve 4 tasks. The first was transmitting data to the OrangePI and then receiving data back. Picture 6 shows the TCP subVI that was created to transmit 9 data points and then receive 9 data points back. By using the built-in TCP network blocks this task was rather simple.

The next task was creating an automatic counter which would help automate the rest of the LabVIEW loops (Picture 2). The TCP blocks were activated by a send button being pressed, however, we couldn't sit there clicking that button all day, so we created a while loop which waited 150 ms and incremented a variable. This variable is used to execute all of the loops in this program.

The next task was figuring out how to draw the robot in real-time and making this image move around on a 2D picture plot. Picture 5 shows the Robot drawing VI that was created. First, we created the image of the robot by plotting points on a graph in Desmos and transcribing the points in the blue array. Here we take the robots X, Y, theta values, and the robot image and combine them in a Rotate angle block. This takes the robot data and rotates the image we created so the image matches the robot's true bearing in real life. Next, we added some offsets which just changed the (0,0) origin point to a place we liked and converted feet to pixels. Then, the finalized (X, Y) pixels are entered into a for loop which goes through and updates the robot's drawn pixel position in the plot. Finally, these pixel points are put in a Draw Multiple Lines block which plotted the robot onto a 2D picture.

The final task was attempting to draw the robot's path and the obstacles detected. Since these two tasks were basically attempting the same task of plotting data while updating to plot to include new incoming data without losing previous plotted info, they were combined. This part of the project took the most time to figure out, but once I figured out that shift registers were required, it was pretty simple. Picture 4 shows how we manipulated the robot coordinates and the obstacle coordinates. Here we connected each set of (X, Y) coordinates and used a Draw Point block which would take the coordinate and draw a single point on the 2D picture. These Draw point blocks were connected to an empty 2D Picture block and then connected to a shift register. This shift register was a second 2D Picture block which allowed us to update this picture without losing any data. We added a button that would bypass the first Picture block to stop and start the tracking of data points to help clear some of the clutter on the screen while testing.

Everything was combined inside a Flat sequence which helped distinguish the 3 stages of the program; Connect to Server, Run Program, Disconnect from Server. This program was a lot of fun to make and really showed the potential of LabVIEW for future projects we may have.

Robot tracking a large box in the room. The priority code was not optimized so the robot took a long time to map the entire box

Schematics

Code

#include "TCPIPServerUARTto28x.h"

union float_char
{
    float val[9]; //changed from 2 to 9 to involve 9 values in the array 
    char bytes[36]; //changed from 8 bytes to 36 to include the 9 floats instead of 2 
};


#define SERFILE "/dev/ttyS2"
#define SERIALBUFFSIZE 1024
float cx; //position of the center(in percentage)
float cy; //position of the center(in percentage)
union float_char to_send;
union float_char received;


/*
 * setup_serial()
 *   sets the serial port up at 115200 baud
 */
int setup_serial()
{
    sd_setup(SERFILE); //starts non-blocking
    sd_ioflush();
}



int TCPIPtransmissionerror = 0;		// Initialize transmission error count
int TCPIPbeginnewdata = 0;
int TCPIPdatasize = 0;

int EchoString = 0;
int numTXChars = 0;

#define INBUFFSIZE (2048)
#define OUTBUFFSIZE (INBUFFSIZE + 2)
char TCPIPMessageArray[INBUFFSIZE + 2]; 

char inbuf[INBUFFSIZE+2]; //changed frmo +2 to +5
unsigned char outbuf[OUTBUFFSIZE];
int accepted_skt;

/*  
 * gs_killapp()
 *   ends application safely
 *
 */
void gs_killapp(int s)
{
  printf("\nTerminating\n");
  gs_quit = 1;
  gs_exit = 1;
  close(gs_coms_skt);
  return;
}
 


/*
 * init_server()
 *   Starts up listening socket
 */
int init_server()
{
  int on = 1;

  // Communications sockets,
  // tcp:
  gs_coms_skt = tcpsock();  
  
  if (setsockopt(gs_coms_skt, SOL_SOCKET,SO_REUSEADDR, (char*)&on, sizeof(on)) < 0) {
	 printf("Error Reusing Socket\n");
  }
  sockbind(gs_coms_skt, gs_port_coms);
  socklisten(gs_coms_skt);
  printf("Listening on port %d\n.",gs_port_coms);
  sock_set_blocking(gs_coms_skt);
}

void tcp_signal_handler_IO (int status)
{
  int i,j;

  int numrecChars = 0;

	
  for (i=0;i<INBUFFSIZE/2;i++) {
    inbuf[i] = '\0';
  }

  numrecChars = read(accepted_skt, inbuf, INBUFFSIZE/2); 
  if (numrecChars > 0)  {
	for (i=0;i<numrecChars;i++) {
		if (!TCPIPbeginnewdata) {// Only true if have not yet begun a message
			if ('*' == (unsigned char)inbuf[i]) {// Check for start char
				TCPIPdatasize = 0;		// amount of data collected in message set to 0
				TCPIPbeginnewdata = 1;		// flag to indicate we are collecting a message
			}
		} else {	// Filling data
			// Dont go too large... limit message to 256 chars  this can be made larger if you change inbuf size
			if ((TCPIPdatasize < INBUFFSIZE) && ((unsigned char)inbuf[i] != '#')) {	
				TCPIPMessageArray[TCPIPdatasize] = inbuf[i];				
				TCPIPdatasize++;
			} else {  // too much data or 255 char received
				if ((unsigned char)inbuf[i] != 255) {// check if end character recvd
					// Not received
					TCPIPtransmissionerror++;
					printf("TXerrors = %d\n",TCPIPtransmissionerror);
				} 
				// Whether or not message terminated correctly, send data to other tasks
				TCPIPMessageArray[TCPIPdatasize] = '\0'; 	// Null terminate the string
				TCPIPdatasize++;  // increment by one so that the Null is copied to shared memory
				printf("Received String:%s\n",TCPIPMessageArray);
				EchoString = 1;
				//Do something with this UART   TCPIPMessageArray[j];
						
				TCPIPbeginnewdata = 0;	// Reset the flag
				TCPIPdatasize = 0;	// Reset the number of chars collected
			}	
		}
	}
  } else {
  printf("numrecChars = %d\n",numrecChars);
  printf("\nReseting\n");
  gs_quit = 1;
  close(gs_coms_skt);

  } 
	     
  // call this kill when kill string is sent
  //      gs_killapp(0);
  

  return;
}




/*
 * run_server()
 *   This function runs until the server quits and it:
 *
 *   1. accepts incoming TCP connections
 *   2. reads from ready sockets and writes incoming messages
 *      to the serial port / controls devices
 *   3. reads from serial port and prints
 */
int run_server()
{
	sigset_t sigio_set; 
	struct sigaction saio;           /* definition of signal action */
	static struct sockaddr_in addr;  
	int i;

	// Accept new connection
	accepted_skt = connaccept(gs_coms_skt, &addr);
	// We don't wanna block either source
	sock_set_nonblocking(accepted_skt);
	int flags = fcntl(accepted_skt, F_GETFL,0);
	fcntl (accepted_skt,F_SETFL,flags|FASYNC);
	fcntl(accepted_skt, F_SETOWN, getpid());

	sigemptyset(&sigio_set);
	sigaddset(&sigio_set,SIGIO); 
	saio.sa_handler = tcp_signal_handler_IO;
	saio.sa_flags = SA_SIGINFO;
	sigemptyset(&saio.sa_mask);
	saio.sa_mask = sigio_set;
	if (sigaction(SIGIO,&saio,NULL)) {
		printf("Error in sigaction()\n");
		return 1;
	}

	if (accepted_skt>0) {
		printf("Connection accepted from %d.%d.%d.%d\n",
		(addr.sin_addr.s_addr&0x000000ff),      
		(addr.sin_addr.s_addr&0x0000ff00)>>8,
		(addr.sin_addr.s_addr&0x00ff0000)>>16,
		(addr.sin_addr.s_addr&0xff000000)>>24);
	}
	printf(".\n");
	while (!gs_quit) {
		sched_yield();
			
		//Here get data from serial port and then print and then send
		if (EchoString == 1) {	
			sscanf( TCPIPMessageArray, "%f %f %f %f %f %f %f %f %f", &to_send.val[0], &to_send.val[1], &to_send.val[2], &to_send.val[3], &to_send.val[4], &to_send.val[5], &to_send.val[6], &to_send.val[7], &to_send.val[8]); //changed to include all 5 values, replaces the next two lines basically
			//to_send.val[0] = keypoints[max_index].pt.x;
            		//to_send.val[1] = keypoints[max_index].pt.y;

			printf("Send String:%.3f %.3f %.3f %.3f %.3f %.3f %.3f %.3f %.3f\n", to_send.val[0],to_send.val[1],to_send.val[2],to_send.val[3],to_send.val[4],to_send.val[5],to_send.val[6],to_send.val[7],to_send.val[8]);
			//changed above line to include 13 values 
			
			
            		sd_write("*");
            		sd_write("*");
            		sd_writen(to_send.bytes,36); //changed from 8 bytes, as each float is 4 bytes and there is 9 floats
            		usleep(50000);
            		sd_write("!");
            		sd_write("!");
           		sd_readn(received.bytes,36); //changed from 8 bytes, as each float is 4 bytes and there is 9 floats
		        printf("RECEIVEvalue1 = %.3f value2 = %.3f value3 = %.3f value4 = %.3f value5 = %.3f value6 = %.3f value7 = %.3f value8 = %.3f value9 = %.3f\n ",received.val[0],received.val[1],received.val[2],received.val[3],received.val[4],received.val[5],received.val[6],received.val[7],received.val[8]);
			//changed above line to include 9 values 
        		numTXChars = sprintf(((char *) outbuf),"%.3f %.3f %.3f %.3f %.3f %.3f %.3f %.3f %.3f\r\n",received.val[0],received.val[1],received.val[2],received.val[3],received.val[4],received.val[5],received.val[6],received.val[7],received.val[8]);
			//changed above line to include 9 values
			write(accepted_skt, outbuf, numTXChars);

			EchoString = 0;
		}
	}
}




/*
 * main()
 *   process command line input
 */
int main (int argc, char **argv)
{
	int index = 0;
	int firsttime = 1;

	if (argc ==2) {
		printf("using port %s\n",argv[1]);
		gs_port_coms = atoi(argv[1]);
	}

//init UART

	to_send.val[0] = 0.1234;
	to_send.val[1] = 0.4567;
	to_send.val[2] = 0.5123;//added in 
	to_send.val[3] = 0.6192;//added in
	to_send.val[5] = 0.7182;//added in 
	to_send.val[6] = 0.7182;//added in 
	to_send.val[7] = 0.7182;//added in 
	to_send.val[8] = 0.7182;//added in 

	printf("Initializing serial port driver %s...\n", "/dev/ttyS2");
	setup_serial();
	printf("...OK\n");

        sd_set_blocking();
        printf(".\n");
        sd_ioflush();

	printf("Setting signal handler...\n");
	signal(SIGKILL, gs_killapp);
	signal(SIGINT, gs_killapp);
	printf("...OK\n");
	while (!gs_exit) {
		gs_quit = 0;

		if (!firsttime) {
			printf("Waiting 2 Seconds to make sure socket data is cleaned from the network.\n");
			sleep(2);
		}

		printf("Initializing listening connection...\n");
		init_server();
		firsttime = 0;
		printf("...OK\n");

		printf("Accepting connections...\n");
		run_server();
	}

}

ME461 Floor Mapping Robot Project

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Final Project Goals

Development

Sensor Integration

Obstacle Avoidance and Pathing

Wireless Data Transmission

Labview

Custom parts and enclosures

ME461 Robot Upgrades

Orange Pi Lite Slim Case Standard

Schematics

Sensor Overview Video

Diagram of Path of Robot

Diagram of Obstacle Avoidance Procedure

Code

LabView VIs

Obstacle Avoidance and PI Communication Code

Orange Pi TCPIP code

Credits

Kevin Kathe

Rounak Chowdhury

Kush Patel

Comments

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ME461 Floor Mapping Robot Project

ME461 Floor Mapping Robot Project

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Final Project Goals

Development

Sensor Integration

Obstacle Avoidance and Pathing

Wireless Data Transmission

Labview

Custom parts and enclosures

ME461 Robot Upgrades

Orange Pi Lite Slim Case Standard

Schematics

Sensor Overview Video

Diagram of Path of Robot

Diagram of Obstacle Avoidance Procedure

Code

LabView VIs

Obstacle Avoidance and PI Communication Code

Orange Pi TCPIP code

Credits

Kevin Kathe

Rounak Chowdhury

Kush Patel

Comments