Xiaoqin Shen

Implementation and evaluation of object-oriented flexible measurement system

Combined with a measurement example, the framework of the Object-oriented Flexible Measurement System (OFMS) is described in detail in this paper. The OFMS adequately takes advantage of the object-oriented technique of the computer software, and is realized in the hardware and software. As a result, it leads the trend of measurement to integration. The emphases of it are on the encapsulation, inheritance, flexible-construction and multi-task options. The concept, the software and hardware system, the anti-disturbing measurement, the error source and the measuring process of the OFMS are studied in detail in this paper. Its construction includes the hardware and software modules. The software module consists of the dynamic modeling and data fusion of the sensors, the database of object-oriented measurement, the expert system of measurement information processing, the test platform, the measurement class library integration and the error self-learning and compensation system. The hardware includes the signal actuating system, the sensor system, the signal transforming system, the measuring system, the analog switch embattling and the measurement post-processing system. The encapsulation and inheritance make the human-computer interface of the measurement system terse and uniform. The flexible-construction and multi-task options make the system having broad expansibility and good economical efficiency. So the OFMS and the Virtual Instruments together direct the developing trend of measuring devices.

Development of 4-DOFs carrying robot for identifying work-piece shape and centroid based on CCD

4-DOFs carrying robot is widely used in the automated warehouses and workshops. According to the differences of the task objects, the automatic identifying system can distinguish from the shape and centroid of the work-pieces carried by the robot. The hardware of the system includes the CCD which is fixed on the end effecter of the rotor and used for collecting images, the laser diode used for measuring the thickness or height of the carried objects and the robot control system based on PC. The image is smoothed by using quadrate window medium filtering and the image edge is picked-up by method of gradient operator. The object outline is identified by the method of self-adapting straight-line fitting process. The position of the object center is calculated using the method of first and zero moment of the identified image in this system. The laser diode is used to distinguish the thickness or height of the object. The distance between surface and bottom of the object can be calculated after the light beam emitted from the laser diode passing through the triangle optical system which is made up of semi-permeable mirror and full reflector. The position on the operating plane of the robot, orientation and center of the carried object can be calculated after the image processed combining the attitude of the rotor end effector. Then the carried object is grasped accurately by adjusting the control command of the rotor end effector. The test indicates that this system has high grasping precision, good anti-jamming ability and good adaptability to field of production.