This paper proposes a simple method for localization using an electronic compass. Electronic compasses are often used to detect the heading of mobile robots. However, electronic compasses have one drawback when used inside a building: they can easily be disturbed by electromagnetic sources (e.g., power lines) or large ferro-magnetic structures (e.g., bookshelves). However, this paper introduces another indoor application of electronic compasses. We take advantage of the magnetic¯eld disturbances by using them as distinctive place recognition signatures. Wē rst gather information about the changing heading as our robot travels along the hallway outside the lab, and then store this information. As the robot traverses the hallway, it gathers the information from the electronic compass and matches it with the pre-stored data. If a match is found, the robot can determine its current position. We use a sequential least-squares approximation approach for matching the signature. The simulation results will show that the robot can distinguish its location by using these signatures.

Problem statement: While classical PID controllers are sensitive to variations in the system parameters, Fuzzy controllers do not need precise information about the system variables in order to be effective. However, PID controllers are better able to control and minimize the steady state error of the system. To enhance the controller performance, hybridization of these two controller structures comes to one mind immediately to exploit the beneficial sides of both categories. Approach: A hybrid fuzzy PID controller for the Electro-Hydraulic Position Servo System (EHPSS) was proposed in this study. The proposed control scheme was separated into two parts, fuzzy controller and PID controller. Fuzzy controller was used to control the piston when the piston locates far away from the target position. PID controller is applied when the piston is near the desired position. Results: We demonstrated the performance of control scheme via experiments performed on the EHPSS. Conclusion:The results from the experiments showed that the proposed hybrid fuzzy PID controller has superior performance compared to individual PID controller and fuzzy controller.

This paper describes how fuzzy control can be applied to a sonar-based mobile robot. Behavior-based fuzzy control for HelpMate behaviors was designed using sonar sensors. The fuzzy controller provides a mechanism for combining sensor data from all sonar sensors which present di®erent information.The behavior-based approach is implemented as an individual high priority behavior. The highest level behavior is called the task-oriented behavior, which consists of two subtasks, wall following and goal seeking. The middle level behavior is obstacle avoidance. The lowest level is an emergency behavior. Each behavior was built as an atomic agent based on the intelligent machine architecture (IMA). The results demonstrate that each behavior works correctly. The HelpMate robot can follow the wall, go to the goal, and avoid obstacles detected by the sonar sensors.

This paper describes how fuzzy control can be applied to sonar based obstacle avoidance of HelpMate mobile robot. Behavior-based fuzzy control for HelpXlate mobile robot was designed. The design and implementation of fuzzy control system is described. The fuzzy controller provides the mechanism for solving sens(,r data fi'om all sonar sensors which present differ-<,.t infl)rmation. Behavior-based approach is implem(~ut(>([ ab all individual high priority behavior. Usint4 I)(~havior-based solves architecture of behavior selection problem. The highest level behavior is called task-oriented behavior, which consists of two subtasks, wall t'ollowing and goal following. The lower level is t)bstacle avoidance behavior. The lowest is an emerg('n('y behavior. Visual Basic 6 code was developed for implementation. The fuzzy inference system was crear(-,d. Helpmate obstacle avoidance was implemented. The result shown that each behavior is work correctly. The HelpMate robot can avoid all obstacles that are det(-,cted by sonar sensors.

Existing fuzzy control methods do not perform well when applied to proportional hydraulic systems (PHS) containing nonlinearities arising from unknown deadzones. In this paper, a two-layered fuzzy logic controller is proposed for controlling a PHS with deadzones. The two-layered control structure consists of a fuzzy logic-based precompensator followed by a usual fuzzy PD controller. This system was implemented for PHS position control. The results show that a two-layered fuzzy logic controller has superior performance compared to usual fuzzy PD controller. In addition, the proposed scheme is robust to disturbance.

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