Aiming at the problem that the excessive friction between the balance tail rope and the branch rope beam of the vertical shaft friction hoist causes serious tail rope wear and affects the safe ...operation of the main hoist, a friction monitoring system between the balance tail rope and the branch rope beam of the main hoist is designed. The friction monitoring system mainly consists of a host computer, an inductive proximity switch, an active infrared radiation sensor and other equipment. The recognition reliability of the friction monitoring system is improved by adopting the concept of double-layer monitoring. The host computer performs audible and visual alarms and controls the operation of the lifting electric control system by monitoring the change of the signal. The results of field tests show that this system improves the reliability of the safe operation of the hoist and meets the actual requirements.
In accuracy grinding processes of screw threads, tool setting is a significant step towards avoiding thread error and ensuring machining accuracy of screw threads. It is a challenge for grinding ...internal screw threads due to the narrow space limitation. This paper proposes an automatic tool setting method for grinding internal screw threads with non-contact proximity switch, which can be effectively applied into realistic situation with low cost. The geometrical features of internal screw threads in the narrow space are measured by non-contact proximity switch and used to determine the initial point of screw helix. The detailed procedures of the method are presented including preliminary adjustment for tool setting, measurement of spiral centerline for internal screw threads, calculation of the initial position of threads helix, and error compensation. Moreover, the experimental platform is developed to verify the feasibility of the non-contact automatic tool setting method. Furthermore, experiments on improved induction distance of proximity switch, axial translational speed, measurement mechanism, and robustness have been carried out to improve the accuracy of the tool setting method. The results show that the measurement mechanism with double-rising-edge level jumping is relatively better on the tool setting precision. And the improved induction distance of proximity switch is basically consistent with its theoretical one, the improved axial translational speed is − 5 mm/s, and the repeat accuracy of tool setting is up to ± 0.002 mm. The results show the economical and effective method is applicable in the actual process of grinding internal screw threads.
This paper introduces a technique employing repeated intermediate positionings, which are controlled by sequential on-off actions of solenoid valves, of a pneumatic cylinder. The motion of the piston ...slider is detected by several proximity switches instead of sophisticated position sensors, which are commonly used in motion control. The designed control system is constructed without a feedback control loop; it operates with only minimal information from the switch signals. We study the precision performance, under various loading conditions, of a pneumatic cylinder enhanced by the use of proximity switches. The repeatability of the system is experimentally found to be on the order of 0.2 mm. This technique will greatly extend the field of application of pneumatic cylinders on automated production lines.
A Smart Clamping Force Control (SCFC) is adapted to hold sensitive workpiece using magnetic proximity switch during a machining operation on the CNC machine tool. It has been ascertained that ...work-holding of different workpiece materials and shapes during machining operation is one of the problems encountered during CNC milling machining operations. This work proposes a novel clamping strategy for workpieces with the aid of SCFC. The purpose of the study is to adjust the forward movement of the clamp and reduce the damage caused by the clamp on the workpiece, this depends on the material of the work-piece. The speed of the clamp is reduced using the inlet flow control throttle valve and a magnetic proximity switch (MPS). It provides careful handling of workpiece and prevent it from damage and as well optimizes the forward movement of the cylinder. The proposed strategy is based on dynamic machine loading in which the impact of applied forces were monitored to optimize the clamping control system of the machine tool. The mode of operation and performance of the SCFC were simulated in the FluidSIM® software, and the validated results was presented on Festo workstation. This work therefore further elucidate the fundamental design criterion for machine tool clamping forces and the sustainable manufacture of its components.
For a control system, the static performance of a sensor is always a milestone of dynamic performance of the system. The static performance of a proximity switch plays an important role due to it ...affects the dynamic properties quality of a mobile robot and the results of dynamic identification. A proximity switch is a common sensor to search a metal guideline for a mobile robot. If the signal of a proximity switch is unstable or noise, it is more disturbance for a mobile robot control. Hence, a static performance evaluation of a proximity switch is basic technology for a mobile robot and will be proposed in this paper.
When a proximity switch is used to search a signal of a metal tape as guideline for a mobile robot, there are giant effect so different metals such as diamagnetism, paramagnetism and ferromagnetism in materials. In this paper, the hand-made measurement system is successful development, and 6 types of metals are measured. Through measurement, the static performance of a proximity switch can be fast evaluated and analyzed, respectively. The experiment result shows that the signals of diamagnetism, paramagnetism and ferromagnetism metal tape in materials are giant differences. By using the developed measurement system of this study, the effects of different metals can be fast determined respectively. And base on this static performance, the dynamic performance of a proximity switch can be fast and precisely evaluated. Determining how to rapidly and efficiently control a mobile robot therefore becomes the key point in using the measurement technique of static performance.
Real-time positioning of thin seam shearer's working position is an important prerequisite to achieve thin seam mining face automation control. Based on the analysis of walking mechanism of thin seam ...shearer and the existing shearer positioning systems, a method was proposed by detecting the shaft angle with the improved thin seam shearer angle encoder. Meanwhile shearer automatic calibration method was designed based on the magnetic sensor by adjusting the error coefficient. The system provides the data support of thin seam shearer automation control.
In this paper, the conveyor belt tearing statistics of Qingdao Port Coal and Mineral Terminal Co. Ltd in 10 years is analyzed to seek two characteristics of conveyor belt after tearing, and also a ...method of using capacitive approach switch and inductive proximity switch to detect the tearing is proposed.
In view of the traditional zero-angle memory device with low precision and to reduce errors caused by manual readout, this paper using electro-magnetic technology, designed a new zero-angle memory ...device based on proximity switch. Experimental results show that the device not only improves the repeatability and reduces the error, but also realize automatic demarcation.
In view of problems of leak-detection and misinformation existed in present detection methods of belt connector state, an image acquisition system of underground belt connector was designed. The ...system adopts inductance-type proximity switch to detect belt metal connector real-timely and also controls digital camera to capture the images of the positions of travelling belt automatically. Then, it uses underground looped network to transfer the images to the ground monitoring room , so as to achieve real-time capturing and processing of the belt connector images and eliminate hidden danger of tearing, tripping of the belt connector in time.
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