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This paper deals with the design of a calibration device for measuring the residual torque of the vehicle brake. It informs about the problems and purpose of the brakes, requirements placed on the brake system, and the design of vehicle brake systems. The practical part of the research contains the design of four versions of the calibration device and the 3D model of the proposed calibration device. There is also a new calibration methodology and calculation of the theoretical fault of the calibration device. An analysis and comparison of the original and new torque sensor calibration methods are presented at the end of this paper. By comparing the original and new calibration methods, it was revealed that the deviations from the required torque value compared to the original calibration version decreased from an average value of 0.154 Nm to 0.0047 Nm, and the variance of the measured values decreased on average from 0.00276 Nm to 2.07 × 10−6 Nm. The proposed new torque sensor calibration method has shown a positive contribution to the accuracy of torque sensor calibration, which as a result will significantly increase the reliability and accuracy of measuring the residual torque of automobile brakes and shorten the measurement time. [ABSTRACT FROM AUTHOR]

MultiCal is an affordable, high-precision measuring device designed for the on-site calibration of industrial robots. Its design features a long measuring rod with a spherical tip that is attached to the robot. By restricting the rod's tip to multiple fixed points under different rod orientations, the relative positions of these points are accurately measured beforehand. A common issue with MultiCal is the gravitational deformation of the long measuring rod, which introduces measurement errors into the system. This problem becomes especially serious when calibrating large robots, as the length of the measuring rod needs to be increased to enable the robot to move in a sufficient space. To address this issue, we propose two improvements in this paper. Firstly, we suggest the use of a new design of the measuring rod that is lightweight yet has high rigidity. Secondly, we propose a deformation compensation algorithm. Experimental results have shown that the new measuring rod improves calibration accuracy from 20% to 39%, while using the deformation compensation algorithm, the accuracy increases from 6% to 16%. In the best configuration, the calibration accuracy is similar to that of a measuring arm with a laser scanner, producing an average positioning error of 0.274 mm and a maximum positioning error of 0.838 mm. The improved design is cost-affordable, robust, and has sufficient accuracy, making MultiCal a more reliable tool for industrial robot calibration. [ABSTRACT FROM AUTHOR]

Featured Application: A standard device of steel measuring tape based on machine vision is used for the intelligent detection of steel measuring tape, with accurate, fast, and automatic characteristics. The application of this device falls within the scope of metrology. Aiming to address the disadvantages of the low automation degree of the traditional steel measuring tape verification device, as well as the high labor intensity of metrologists, high time costs, and low measurement accuracy, this paper develops a new automatic steel measuring tape calibration device based on machine vision technology. In this study, the key components, such as the tape-winding mechanism, machine vision system, force measuring device, and tape-retracting device, were designed. Three different scribed line identification and location algorithms, processing the longest line, the closest to the starting line, the highest line, etc., were designed to adapt to different types of steel measuring tape. Lastly, indication error and measurement repeatability tests were carried out. The results showed that the standard device can carry out the verification and calibration of steel measuring tape, and the maximum repeatability of the indication error of the test objects was 0.025 mm, 0.038 mm, and 0.030 mm, respectively, and the indication error of each object was within the allowable error limits. The uncertainty evaluation of the indication error of each test object was 0.16 mm, 0.54 mm, 0.78 mm, which was not more than one third of the maximum permissible error value. Hence, the measuring principle, method, and procedure of the calibration device are shown to be scientific and feasible. [ABSTRACT FROM AUTHOR]