Shanlin Liu

Bio: Shanlin Liu is an academic researcher from Hefei University of Technology. The author has contributed to research in topics: Orientation (geometry) & Rotor (electric). The author has an hindex of 5, co-authored 11 publications receiving 78 citations.

Integrated inspection instrument for friction torque of rolling bearing

Abstract: The utility model discloses a novel comprehensive detecting instrument for detecting the friction torque of a rolling bearing, which comprises a driving module, a bearing bracket and a pressurizing module. Two bearing-clamping modules are respectively mounted in the upswept slanting rectangular holes in the lower waists of both sides of the bearing bracket; a radial jump measuring module is fixed in a slip gauge on the right side plate of the driving module and nearing the part of a driving shaft; a bearing pretightening force measuring module mounted on the left side plate of the bearing bracket comprises upper and lower flexible supports and two lockable slide blocks respectively and movably nested on the upper and lower flexible supports, and two inductive transducers respectively pass through the respective arc-shaped lock blocks and are respectively locked on the slide blocks by bolts. The transducers of the utility model has the advantages of high positioning precision and many measuring parameters; the measured data are stable and reliable; in one clamping, the utility model can fulfill the detection of the parameters of a bearing part, such as friction torque, pretightening force, geometric tolerance, etc.; the utility model can detect deep groove ball bearings, angular contact ball bearings, self-aligning ball bearings, cylindrical roller bearings, self-aligning roller bearings, conical roller bearings or thrust ball bearings.

A New Method for Measuring the Rotational Angles of a Precision Spherical Joint Using Eddy Current Sensors.

Abstract: Precision spherical joint is a spherical motion pair that can realize rotation with three degrees of freedom. This joint is widely used in robots, parallel mechanisms, and high-end medical equipment, as well as in aerospace and other fields. However, the rotation orientation and angle cannot be determined when the joint is in passive motion. The real-time determination of the rotation orientation and angle is crucial to the improvement of the motion control accuracy of the equipment where the joint is installed in. In this study, a new measurement method that utilizes eddy current sensors is proposed to identify the special features of the joint ball and realize angle measurements indirectly. The basic idea is to manufacture the specific shape features on the ball without affecting its movement accuracy and mechanical performance. An eddy current sensor array is distributed in the ball socket. When the ball head rotates, the features on the ball opposite to the sensor, as well as the output signal of every eddy current sensor, change. The measurement model that establishes the relationship between the output signal of the eddy current sensor array and the rotation direction and angle of the ball head is constructed by learning and training an artificial neural network. A prototype is developed using the proposed scheme, and the model simulation and feasibility experiment are subsequently performed. Results show that the root mean square angular error of a single axis within a range of ±14° is approximately 20 min, which suggests the feasibility of the proposed method.

Synthetic inspection tester for shaft element

Abstract: The invention discloses an integrated inspection device of axis parts, which consists of a granite base, a granite air floating measuring guideway and slipway, a granite air floating bearing guideway and slipway, a head frame, a tail frame, a plurality of measuring modules and a long grating ruler Adopting the structure can achieve the integrated measurement to the axis parts, the integrated measurement of the axial dimensions of the axis parts and a plurality of position errors can be achieved by one clamping, and the inspection device has the advantages of simple structure, easy operation, and high precision

A New Modeling Method of Angle Measurement for Intelligent Ball Joint Based on BP-RBF Algorithm

Abstract: The rotation orientation and the angle of precision of an intelligent ball joint cannot be automatically obtained in passive motion. In this paper, a new method based on a Hall sensor with a permanent magnet (PM) is proposed to identify the spatial rotation orientation and angle. The basic idea is to embed a PM on a ball while the Hall sensors are arrayed into the ball socket. When the ball rotates, the Hall sensor array detects the variation of the magnetic induction intensity in space. By establishing a mathematical model between the variation of the magnetic induction intensity and the orientation and angle of rotation, the rotation angle in the space where the ball is located can be inversely solved. The establishment of the theoretical model is based on the theory of the equivalent magnetic charge method, which has a few native defects that cannot be overcome by itself. This paper presents the relationship between the magnetic induction intensity change and the rotation angle of the ball in space, which was constructed by an artificial neural network (ANN) and will simplify the mathematical model, shorten the operation time, and improve the efficiency of real-time detection. Based on the simulation analysis, the optimal matching scheme between the PM and the magnetic effect sensor was determined, and the structural parameters of the ball joint prototype were optimized. The data training and comparison test of the neural network model were completed on a self-developed calibration device. The experimental results show that for a ±20° measurement range, the average errors of the uniaxial measurements are 1′51″ and 1′55″ on the two axes, respectively. At present, the measurement accuracy of the prototype is still relatively low; however, this idea of modeling based on ANN removes the shackles of mathematical modeling, reminding us that we can consider the design of sensors or complete geometric measurement modeling from a new perspective.

Device for rapidly detecting size parameters of cylinder type excircle shape

Abstract: The invention discloses a device for rapidly detecting size parameters of a cylinder type excircle shape, and aims at providing the rapid detection device simple in structure, high in measuring efficiency and capable of improving the measuring precision. A CCD camera (5) whose lens just faces a clamped detected workpiece (2) is arranged over the clamped detected workpiece, the CCD camera (5) collects images of the clamped detected workpiece which is driven by a servo motor to rotate, the collected calibration position size of each groove is converted into a digital signal, the digital signal is transmitted to a circular grating (4) fixed on a main shaft of the servo motor, the angular displacement of the detected workpiece, namely a moving object, is obtained, a linear array photosensitive tube calculates the position size of each groove via a computer image processing software system input by a reading head device, parameters including the width, the position accuracy and the verticality of the calibration groove of the detected workpiece are displayed and printed. The device can be used to overcome the disadvantages that errors of manual measurement influence test results a lot and cause low measuring efficiency.

Platform for testing performance of main shaft of machine tool

Abstract: The invention relates to a platform for testing the performance of a main shaft of a machine tool. The platform comprises a test bed, a main shaft unit, a main clamping device, an auxiliary clamping device and a detection bar, wherein the main clamping device and the auxiliary clamping device are arranged on the test bed and used for fixing both ends of the main shaft unit; and one section of thedetection bar is penetrated into an axis of the main shaft unit, and the other section of the detection bar is contacted with a dynamic precision detection device and a thermal deformation measurement device respectively; the dynamic precision detection device is fixed on a transverse guide rail capable of moving along an axial direction of the main shaft unit; and the thermal deformation measurement device is fixed on a longitudinal guide rail capable of moving along a longitudinal direction of the main shaft unit. By the platform, the technical requirements on fixing of the main shaft, installation and moving of a measurements instrument and the like of fixtures or clamps which meet an experimental requirement can be met, so that technical performance data of a plurality of points of the main shaft can be tested conveniently and comprehensively.

Multi-freedom degree laser displacement sensor system and spiral bevel gear measurement method

Abstract: The invention relates to the technical field of gear measurement, in particular to a structure of a multi-freedom degree laser displacement sensor system and a spiral bevel gear measurement method of a device based on the measurement system. The system consists of a laser displacement sensor and a support with the spatial orthogonal axial rotational freedom degree. During measurement of the spiral bevel gear, the rotational pose of the sensor support can be adjusted to allow the laser displacement sensor to keep the same spatial inclined pose with the to-be-measured arc-shaped tooth line as far as possible, thereby ensuring that light spot light sources on the to-be-measured gear tooth face irradiated by laser emitted by the sensor can be reflected on a receiving window of the sensor. Thus, in a measurement process of the gear, acquired data is complete and effective. The system and the method are characterized by simple measurement equipment structure, easy operation and high flexibility.

Device for detecting coaxiality of shaft parts by use of laser

Abstract: The invention discloses a device for detecting coaxiality of shaft parts by use of laser. The device comprises feet, a fixed seat, a rotating motor, a rotating tip, a holder and a laser detection device, wherein the feet are symmetrically arranged at the bottom of the fixed seat, the rotating motor is arranged in the middle part of the feet, the rotating tip is connected with the rotating motor, the holder is arranged on the upper part of the fixed seat, and the laser detection device is arranged at the left side of the holder. In this way, the device for detecting the coaxiality of the shaft parts by use of laser is simple and practical in mechanism, precise in detection, accurate in positioning, efficient, and capable of ensuring small coaxiality error between various shaft parts and improving the product machining quality.