Development of an automatics parallel parking system for nonholonomic mobile robot

This paper depicts the development of backward automatic parallel parking system for nonholonomic mobile robot. The configuration of the system consists of ultrasonic sensor, rotary encoder, controller, and actuators. The path planning algorithm is developed based on the data acquired from the sensor. The proposed idea of the path planning is based on the geometrical equations in which the needed information is referring to the distance between the mobile robot and the adjacent object. The ultrasonic sensor and rotary encoder respectively used to detect parking area and measure the detected space. A PIC32MX360F512L microcontroller is used in order to generate the algorithm and control the movement of the mobile robot. System implementation is briefly described to depict the system as a whole. Experimental results are presented to demonstrate and validate effectiveness of the technique used

Comparative analysis of simplified and standard fuzzy logic controller in vector controller PMSM

This paper presents a comparative analysis of simplified fuzzy logic controller (FLC) for speed performance in vector-controlled permanent magnet synchronous motor (PMSM) drive. The control strategy focuses on fuzzy rule basewhich are contribute to some level of output in obtaining the desired performance. The objective of this research is minimizing the number of rule base used by the PMSM drive besides erform desired output. Two FLCs with reduced rule base (9- rules and 7-rules) are designed and the performance results are compared and ernluated with the standard FLC (49-rules). The simplification of rule base is determined by eliminating some of rule bases that are infrequently fired by the PMSM drive. The standard FLC consists of 49-rules which are determined based on common criteria from many literatures. Two simplified FLCs consist of 9-rules and 7-rules are obtained by knowledge and experience. The simulation results show both simplified FLCs obtain nearly equivalent performance with the standard FLC. The performance of all FLCs over load disturbance and parameter variations are compared a

An Improved Approach for Automatic Parallel Parking in Narrow Parking Spaces

In 2014, there are more than 500,000 parking lot collisions, which is a 4% increase compare to 2010. Many cars are being produced every day, so that the parking spots are designed to be smaller, in the meantime, the size of cars has outgrown the size of parking space since the automakers have been making larger vehicles to favor customers\u27 demands for larger interior spaces. As a consequence of smaller parking spaces, the possibility of human operational errors is significantly increased, which subsequently leads to accidents and traffic problems. This paper proposes an automatic parking method for parallel parking, which can be used to park vehicles in a narrower space to reduce the chances of parking lot collisions. It is based on the kinematic model and could be easily combined with other automatic parking approaches such as fuzzy logic and artificial neural network, ultimately making the parallel parking process more effective

The design of innovative epicyclic mechanical transmissions : application to the drives of wheeled mobile robots

Epicyclic mechanisms have found wide applications in industry, especially in automobiles and robotics. Low efficiency due to the high gearing power occurring in an epicyclic train is an important problem. This thesis develops a novel family of epicyclic transmissions, based on cams and rollers. This kind of cam-based mechanical transmissions, Speed-o-Cam (SoC), offers features such as high stiffness, low backlash, and high efficiency.We develop multi-lobbed cam profiles, the sun cam and the ring cam, which comprise an epicyclic cam train (ECT) with the roller follower. New design criteria are established: the generalized transmission index (GTI) and the contact ratio in cam transmissions. The GTI is an index that quantifies the force transmission quality in a mechanism, thereby generalizing the pressure angle, the transmission angle, and the transmission index (TI) proposed by Sutherland and Roth in 1973. The contact ratio is an index of the quantity of overlap occurring between two conjugate cams during transmission. A contact ratio greater than unity guarantees smooth motion during operation. In order to avoid "poor" transmission, we apply an undercutting technique on the cam profile to achieve a smooth motion.We introduce two new concepts, virtual power and virtual power ratio, and derive an original algorithm to compute the efficiency in an epicyclic train upon the assumption that power loss is due only to friction upon meshing. The results show that friction has a larger effect on the total efficiency of an epicyclic train than on a simple train. Examples are given to validate this algorithm, by comparison of our results with previous works.The dual-wheel transmission (DWT), proposed elsewhere using epicyclic gear trains (EGTs), is designed here with epicyclic trains of cams and rollers. We optimize the DWT to achieve a compact design and a high transmission performance. Furthermore, we define the total transmission index (TTI), which allow us to evaluate the final DWT design. Two virtual prototypes of the DWT, the central and the offset versions, are generated: the former is capable of quasi-omnidirectional mobility, the latter of full omnidirectional mobility.Finally, we include a general kinematic analysis of wheeled mobile robots (WMRs) with single-wheel drives and apply this method to WMRs with DWT units; then, we obtain symbolic solutions to the direct kinematics (DK) and inverse kinematics (IK) problems, for both central and offset types of units