It is a C-based language that offers both traditional text based programming as well as drag-and-drop graphical programming. However, this algorithm could not be implemented but rather a solution I developed based on my understanding of the concept of the HIMM technique and the CMU mapping technique from which the HIMM was developed from.ROBOTC Blog ROBOTC Forums ROBOTC Wiki (API) ROBOTC Google+ Hangouts Cool ROBOTC Projects Xanders Blog ROBOTC 4.x for LEGO MINDSTORMS ROBOTC 4.x for VEX.RobotC is the most popular programming language for VEX EDR Cortex and VEX IQ. In the project proposal submitted, the focus of the project was on motion planning and mapping using the Histogramic In-Motion Mapping (HIMM) technique. The overall concept of my final robotics project was to design and build an exploration robot that would scan its environment and build a map that accurately represents that environment. Arduino Installing Drivers Robotc Api Guide Arduino Uno Arduino Mega 259 Sparkfun Electronics Arduino Installing Drivers Robotc Api Guide Https Www Jameco Com Jameco Products Prodds 2170222quickguide Pdf Plastic Scribbler Affordable Easy To Use 3d Printers Arduino Ide And Drivers Installation Windows Xp.
Design ConceptNXT there exists a program called RobotC 16, which is much more complete than the NQC. Unlike the excitement from reading, actually executing this project was awesomely tedious. Deeply thinking about the HIMM and SLAM (Simultaneous Localization And Mapping) techniques was thrilling especially comparing it to how easy it is for humans to get the sense of their environment and simply know where they are and move around flawlessly.
This idea just like the implementation of the actual HIMM technique required the whole project to accommodate a certain level of randomness and unpredictability that would make the project difficult to complete considering the limited time frame.ROBOTC Natural Language - VEX Cortex Reference: 2011 Carnegie Mellon Robotics caem For use it VEX Robotics Sstems ROBOTC Natural Language - VEX Cortex Reference 1A more simple design concept was developed to eliminate the element of randomness and unpredictability. The encoders have 360 counts per single revolution of the motor.The initial designs of the project after a few brainstorming sessions before drawing up the project proposal got outrageously out of scope with the concepts of autonomous localization of the robot. Each motor is equipped with an integrated encoder that can be used to determine the current position of the motor. There are four motor ports on the EV3 labeled A, B, C, and D. Our Function Library (Updated Spring 2013) EV3 - Motor Commands.
Robotc Api Series Of Cells
This module had functions for moving one cell forward, turning 45 and 90 degree right and left, determining the bearing of valid neighboring cells and moving appropriately to them.Also, the same robot architecture was used with slight modifications to accommodate the four sonar sensors. To send the map data from the robot to a remote site for visualization.Building off from the designs used in the Wave Front planning task, the fundamental code for moving to a series of cells making a path was already available (i.e. To visit every cell in the grid to generate the map representation. To use a mathematical model to generate the senor output into information for the map. To scan the four main sides of the robot.
Despite that, already existing implementations of these algorithms that suited the project I was working on proved futile. Most of the results of my search pulled up concepts that had to do with graphs like the Travelling Salesman Algorithm and other Graph Coverage Algorithms. I spent a lot of time searching for ideas and already existing algorithms that insured that every cell in a grid would be accurately covered in the most efficient manner. The positioning of the sensors gave a fairly complete view of the area around the robot though not a complete 360 degree panoramic view.The next critical and ultimately the most challenging task was to develop a coverage algorithm that would allow the robot visit every cell in a given grid.
Move to the first valid neighboring cell. Cells that have not been visited, cells that have no obstacles and cells that are not outside the defined area of the map. Find all the valid neighboring cell of the current location i.e. The fundamental theory of this Path Module is Also, the graph coverage algorithms did not accommodate the presence of dynamic obstacles present in the environment.After, several attempts of designing, testing and redesigning of a model that would allow the robot efficiently cover every cell in a given grid while accommodating the presence or absence of obstacles, a solution was finally developed (i.e.
The approach used in the HIMM algorithm was understandable in theory but difficult in implementing. The Wave Front plan and re-planning backtracking concept catered from new obstacles that blocked already covered paths and provided options no matter the situation.The next sub task was to translate the senor readings into a mathematical function that would be used in building the map. Because, the earlier algorithm retracted along the path already covered, when an obstacle gets in the way of the old path the algorithm failed. This was because, the back track idea used then, was to keep track of all the covered cells and undo each move (by going back the path covered) until an unvisited neighbor cell is found. Prior to using the Wave Front backtrack idea, the algorithm run over a 100 time in order to cover just a 5×5 grid map.
So an obstacle that is detected 100cm away has a grid cell range value of 100/ 45 = 2.222, which is about 2 cells away This meant that every obstacle was known not just by the distance in centimeter but also by the number of cells away.I.e. The readings are then converted into the grid cell range values by dividing the readings by the length of one grid cell. Take sonar readings from the four sensors (an average of 10 readings was always taken to make up for the noise encountered with the sensors). The theory underpinning this module was as follows
A cell with a value of 7 cannot be re-updated except on the event when the grid cell value of that cell is determined to be 1 (i.e. The current cell is given a value of 7 to indicate that it is certainly free. When the robot moves to the next cell, the same procedure is repeated as shown in Figure 4 and 5 and Figure 6 and 7. As illustrated in Figure 2 and 3, the four neighbors of the current location are updated with values that represent the number of cells between an obstacle and the current location cell. North, South, East or West) the appropriate immediate four neighboring cells (because only four sensors were mounted) of the current location were updated to the grid cell range values.
Robotc Api Bluetooth Communication Projects
This module did the following things After studying the RobotC API and experimenting with the ideas used by other RobotC NXT Bluetooth communication projects online, a communication module was developed. I downloaded source code that implemented a java Bluetooth server from ( ). This technique also captures changes to the obstacle present or absent in the environment without erratically changing certainly free cells.The next sub task of the project was to work on communicating with the remote Bluetooth server. Continuously updating the four neighboring cells of each grid cell builds a map that adequately represents the environment.
Shutdown the Bluetooth server after completion.The robot after establishing communication with the Bluetooth server sends initial data that is used to initialize certain parameters on the server side. Activate the communication stream to write raw bytes of data. Search for and pair with my laptop on port 2. Set the robot Bluetooth visibility feature to discoverable.
The algorithms I developed were mostly my own understanding of the concepts presented in the readings and research I had done. As illustrated in Figure 8, cells with the value of 0 are unexplored and have a gray color, cells with the value of 7 are certainly free and have the color green, cells with the value of 1 are certainly occupied and have the color red, the current cell location is color coded yellow while any other value between 2 and 6 have the color blue and are in the known unvisited cell list.It is critical to point out that, I did not fully understanding the implementation of the HIMM technique I studied. This visual component was developed from java applet code used by Programming II student in one of their assignment. Also, a color coded interface of the grid displays the information being sent from the robot for better visualization.
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