Because it is superior in local sensing, tactile sensing for environment recognition has been studied. In this paper, a contact force and position sensor for recognizing the environment and controlling the grasp force is proposed. The sensor incorporates four pairs of quartz resonators mounted in a robot finger and can measure two-dimensional contact force and one-dimensional contact position along the finger. The force sensor is insensitive to electrical noise since the output is a frequency which shifts in response to a change in the external force. This type of force sensor also has quick response, high sensitivity, high resolution and wide bandwidth. The performance of the sensor was examined experimentally. To demonstrate the capabilities of the sensor in recognizing an environment, twodimensional shapes were reconstructed by tracing the surface with the sensor.

In the following contribution a sensor and control system is introduced, that makes the recording of the joint geometry and the corresponding settlement of the parameters of the welding process possible. This is based on a new method, which permits the determination of the local joint geometry from the welding currents by the known through the arc sensing. It also allows the regulation of the filling height of the welded seam. A special diligence was putting on a high robustness of the solution to become fair to the particularly rough requirements on a mobile automatic assembly welding machine at the final assembly of large steel components.

In this paper, we propose a novel obstacle detection system using Ring Beam System (RBS) for mobile robots. This system consists of RBS with a cone mirror, a spherical mirror and a CCD camera. The principle of this system is same as triangulation. The advantages are having no moving parts and detecting all obstacles around the robot simultaneously. Firstly, we calculate a relationship between the position of bright point on picture from CCD camera and the distance to obstacles. Next, we show developed experimental device and results of obstacle detection.

When using robots in automated production it is necessary to use different end-effectors (grippers, tools, measuring units) built in the last robot wrist for handling, welding, machining, assembling, etc. the workpieces. The end-effector is one of the main parts of the robot, which connects the robot with the working environment and gives the possibility to make manufacturing more flexible. It is necessary to replace the manned inspection with sensors to increase the quality of the products and the reliability of the robotized operations. To eliminate the disturbances during monitoring the sensors give information about the end-effector to the robot control. The end-effectors should be tested either after the development of prototypes or before their selection for application. The measuring test gives the most important technical data about the end-effectors, such as position accuracy, static and dynamic stiffness, load capacity, etc., which show whether they are suitable for the given tasks, operations or not. The authors give a short overview about the grasping force monitoring of the grippers, the monitoring of end-effectors using a 6Dforce- torque sensor built in the last robot wrist and the measuring tests of an endeffector changer and a RCC-unit.

For current known piezoresistive silicon pressure sensors, the pressure to be measured is transformed into an elastic deformation of the strongly bounded silicon diaphragm. The resistance value of the implanted piezoresistors on the silicon diaphragm is modified through the resulted mechanical tensions on the material. The etched silicon diaphragm demonstrates a limited burst tension, so that the usual silicon pressure sensors with a diaphragm can only be utilised to measure a maximal pressure of 10³ bar.
The pressure sensitive element is made up of a not thinned silicon chip with piezoresistors on its upper surface and of a whole-surface glass substrate (Pyrex) bonding connection on its bottom side. The different Young moduli of Silicon and Pyrex implies, by all sided-pressure load, the appearance of mechanical tensions in the bounding surface between the two materials. These mechanical tensions in the silicon chip produce a modification of the piezoresistor resistance implanted in the upper surface because of the piezoresistive effect.