Obstacle Avoidance Algorithm Based on Velocity and Orientation Controls of Differential Drive Automatic Guided Vehicle
- Alternative Title
- 차동 무인 운송차량의 속도 및 방향제어에 기준한 장애물 회피 알고리즘
- Abstract
- Automatic Guided Vehicles (AGV) is common equipment to transport the materials in production process. To guarantee the safety of workers while the AGV moves around inside the factory, the moving object tracking and avoiding algorithm should be applied on the AGV.
This thesis proposes an obstacle avoiding algorithm based on velocity and orientation controller for differential drive Automatic Guided Vehicles (AGV) system to avoid the stationary and moving obstacle in industrial environment. This algorithm can works in unknown environment, and guarantees the reachability condition of goal point. To do this task, the followings are done. Firstly, the system configuration of AGV is described. A real AGV system is developed with several interconnected devices such as industrial PC as main controller, laser measurement system for obstacle detection, laser navigation system for positioning, motors for actuator and batteries for power supply. Secondly, mathematic modeling of the AGV is presented to understand its characteristic and behavior. A velocity and orientation control is proposed based on optimal control method. The objective of the controller is to make the AGV navigate to the desired direction decided by avoidance algorithm with profiled velocity. Thirdly, the obstacle avoidance algorithm is proposed. This algorithm has several abilities such as: to detect the moving objects, to predict the velocity and direction of moving objects, to predict the collision possibility and to plan the avoidance maneuver. For sensing the local environment and positioning, the laser measurement system LMS-151 and laser navigation system NAV-200 are applied. Based on the measurement results of the sensors, the stationary and moving obstacles are detected and the collision possibility is calculated. The velocity and direction of the obstacle are predicted using Kalman filter algorithm. Collision possibility, time, and position can be calculated by comparing the AGV movement and obstacle prediction result obtained by Kalman filter. Finally, the avoidance maneuver using the well known tangent Bug algorithm is decided based on the calculation data. Finally, the effectiveness of the proposed algorithm is verified using simulation and experiment. Several examples of experiment conditions are presented using stationary obstacle, and moving obstacles. The simulation and experiment results show that the AGV can detect and avoid the obstacles successfully in all experimental condition.
- Issued Date
- 2013
- Awarded Date
- 2013. 2
- Type
- Dissertation
- Publisher
- 부경대학교
- Affiliation
- 부경대학교 대학원
- Department
- 대학원 메카트로닉스공학협동과정
- Advisor
- 김상봉
- Table Of Contents
- Acknowledgements
Contents .............................................................................................. i
ABSTRACT ...................................................................................... iii
List of Figure ..................................................................................... v
List of Tables .................................................................................. viii
Chapter 1: Introduction ................................................................. 1
1.1. Background and Motivation ................................................. 1
1.2. Previous Study...................................................................... 4
1.3. Objective and Research Method .......................................... 8
1.4. Outline of thesis and contribution ........................................ 9
Chapter 2: System Description.................................................... 11
2.1. Mechanical Design ............................................................. 11
2.2. Electrical Design ................................................................ 14
2.2.1. Sensors .................................................................. 15
2.2.2. Controller .............................................................. 23
2.2.3. Actuator ................................................................ 25
2.2.4. Power supply ........................................................ 26
2.3. Software development ........................................................ 28
Chapter 3: System Modeling ....................................................... 31
3.1. Characterization of wheels ................................................. 33
3.1.1. Fixed standard wheel for driving wheel ............... 33
3.1.2. Castor wheel ......................................................... 34
3.2. Kinematic modeling of differential drive AGV system ..... 35
3.3. BLDC motor modeling....................................................... 41
3.4. Velocity and orientation controller design ......................... 48
3.5. Full structure of AGV control algorithm for velocity and orientation control. .............................................................. 53
Chapter 4: Obstacle Avoidance Algorithm ................................ 54
4.1. Obstacle Detector ............................................................... 54
4.2. Moving Object Tracking Based on Kalman Filter ............. 56
4.3. Collision Possibility Prediction .......................................... 58
4.4. Obstacle Avoidance Policy ................................................ 60
Chapter 5: Simulation and Experimental Results ..................... 62
5.1. Simulation result ................................................................ 64
5.1.1. Velocity and orientation controller ....................... 64
5.1.2. Obstacle avoidance algorithm .............................. 70
5.2. Experimental Results.......................................................... 73
5.2.1. Velocity and orientation controller ....................... 73
5.2.2. Obstacle avoidance algorithm .............................. 76
Chapter 6: Conclusions ................................................................ 80
6.1. Conclusion .......................................................................... 80
6.2. Future works ....................................................................... 82
References ........................................................................................ 84
Publications and Conferences ........................................................ 91
Apendix A ........................................................................................ 93
- Degree
- Master
- Appears in Collections:
- 대학원 > 메카트로닉스공학협동과정
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