Papers by Keyword: Laser Tracker

Abstract: High performance servo system is the basis of fast tracking and precision measurement of laser tracker, and drive circuit is the hardware guarantee of the control algorithm in the system. This paper is concerned with the designed drive circuit of Permanent Magnet Synchronous Motor (PMSM). First, control system model of PMSM is introduced, as well as the PM10CSJ060 Intelligent Power Module (IPM) working principle. Then the drive circuit based on IPM is designed and applied in servo system. Experimental results show that the drive circuit is reliable and stable, with strong anti-interference function, can meet the performance requirements of laser trackers.

Abstract: Hydraulic press occur elastic deformations in the working status. The deformation will affect the precision of the products. This paper expounds the method of using Laser tracker test rigidity of THP11-10000A isothermal forging hydraulic press. And we test the deformation of the lower bean, fit the date and compare with fitting of the finite element simulation results. The validity and the accuracy of the simulation results are verified.

Abstract: Calibration of Laser Tracker systems is based most times in the determination of its geometrical errors. Some standards as the ASME B89.4.19 [1] and the VDI 2617-10 [2] describe different tests to calculate the geometric misalignments that cause systematic errors in Laser Tracker measurements. These errors are caused not only because of geometrical misalignments and other sources of error must also be taken in count. In this work we want to state the errors in a kinematic form. Errors will be split in two different components, geometric and kinematic errors. The first ones depend on the offsets, tilts and eccentricity of the mechanical and optical components of the system. Kinematic errors are different for every position of the Laser tracker, so they will be formulated as functions of three system variables: distance (R), vertical angle (V) and horizontal angle (H) usually called d, φ and θ. The goal of this work is to set up an evaluation procedure to determine geometric and kinematic errors of Laser Trackers.

Abstract: This paper aims to present different methods of volumetric verification in long range machine toll with lineal and rotary axes using a commercial laser tracker as measurement system. This method allows characterizing machine tool geometric errors depending on the kinematic of the machine and the work space available during the measurement time. The kinematic of the machine toll is affected by their geometric errors, which are different depending on the number and type of movement axes. The relationship between the various geometrical errors is different from relationship obtained in machine tool whit only lineal axes. Therefore, the identification strategy should be different. In the same way, the kinematic chain of the machine tool determines determines the position of the laser tracker and available space for data capture. This paper presents the kinematic model of several machine tools with different kinematic chains use to improve the machine tool accuracy of each one by volumetric verification. Likewise, the paper thus presents a study of: the adequacy of different nonlinear optimization strategies depending on the type of axis and the usable space available.

Abstract: As general methods can no longer be used to measure super-large gears, their manufacturing accuracy, performance and quality cant be guaranteed. In this paper, after introducing the characteristics, measuring requirement and the state of arts of inspection of super-large gears, a laser tracker and CMM based measuring technology, proposed by Shi, was presented, and the key techniques were discussed. By taking full advantage of the characteristics of a laser tracker and a coordinate measuring apparatus, the super-large gears positioning problem, which was to determine the relationship between the instrument and workpeice, was solved. Thus, the gears profile, helix, and topology error etc. could be measured. Experiments have been carried out to verify the effectiveness of the method. The results showed that the proposed method could be used to measure super-large gears with the diameters up to 10m.

Abstract: A digital flexible assembly system is developed which is used to assemble one fuselage large component of a large aircraft. The laser tracking metrology system is the important part of the flexible assembly system. The metrology system is composed of three modules: laser tracking measurement module, data processing module, and real-time motion simulation module. The laser tracking measurement module is mainly completing the measurement functions of the laser tracker. Data processing module is the core module of the metrology system, and is responsible for all data computation and transmission in assembling and positioning the aircraft component. The real-time motion simulation module provides the three-dimensional scene simulation of the assembly to the users and gives the users a more intuitive understanding of the assembly process. This paper introduces the system structure and working principle of the developed metrology system which based on the laser tracker. The application of the metrology system and the flexible assembly system can greatly improve the assembly accuracy.

Abstract: The paper introduced the application of laser tracker in the 3D alignment and installation of accelerator. USMN(Unified Spatial Metrology Network) in the SA(SpatialAnalyzer, a software) was used to solve 3D control-survey network in l00m scale, the tracker with SA can measure data and check results for fiducialization, guide the magnets installation and best-fit smoothing orbit. SA made the data stream consistent and reliable, and final the accuracy of 0.15mm transverse over 10m distance. this method also can be used in the installation of great science facility.

Abstract: To improve the machining precision and reduce the geometric errors for 5-axis machine tool, error model and calibration are presented in this paper. Error model is realized by Denavit-Hartenberg matrixes and homogeneous transformations, which can establish the relationship between the cutting tool and the workpiece. The accuracy calibration was difficult to achieve, but by a laser approach, the errors can be displayed accurately which is benefit for later compensation.

Abstract: Different techniques of volumetric verification for long range machines are presented in this paper. Its working principle is based on captured points that can be distributed or not, through laser tracker (LT) or a measurement instrument that is generally of large scale. The developed model allows us to characterize the different errors in the machine tool to study, depending on its kinematics and geometry. Obtaining the transformation matrices that define the kinematics of the machine tool (MT) including the measurement system in the kinematic model, it is possible to relate the coordinates of the tool with the coordinates of LT. The best combination of parameters, techniques and models were obtained through the realization of a large number of synthetic tests based on non linear optimisation techniques

Abstract: To evaluate the profile error of manufacture mainly caused by geometric error of machine tool, this paper proposes a geometric error identification and profile error simulation method. The identify method measures each axis of machine tool based on laser tracker, then using the least square method to fit the axis, as a result the coordinate system of each axis can be built. The geometric error of machine tool can be gained by analysis of the coordinate system. Building the kinematics model of large-scale multi-axis NC machine tool considered the geometric error, then using MATLAB and UG second development to achieve simulation of profile error.