Most of the arm lifts used in today’s industry are designed and manufactured based on the scissor mechanism. Such schemes have one drawback: when the mechanism is raised, their connection points with the base and the movable platform narrow, which leads to a let-down in its stability. This article proposes a new scheme for the lifting device, which eliminates the above disadvantage of scissor schemes. In the scheme developed by the authors, the joints connecting the mechanism to the moving platform and the base are fixed, which means that the distance between the connection points does not change, leading to its stable operation. The mechanism consists of one group of links of the second class and two groups of links of the fourth class. The article focuses on the stability of an automotive lift’s design when moving with a load. The article presents the results of a kinematic and kinetostatic analysis, a study of the stability of the lift and the results of studies of an experimental sample of the developed lift. The methods presented in this article allow for the design of automotive lifts with new lever mechanisms, as demonstrated by computer modeling and experiments.

The structural and positional analysis of planar linkage mechanisms containing higher-class Assur groups requires the generation and solution of systems of algebraic kinematic equations. This paper presents algorithms for the automated analysis of such mechanisms based on an information matrix model. The proposed representation describes a mechanism as a system of material points connected by geometric constraints and provides a unified framework for algorithmic processing of mechanism structure and parameters. A square-matrix information model is developed to store structural and geometric information of a mechanism. Based on this model, three algorithms are proposed: (i) an algorithm for structural analysis and determination of mechanism mobility, (ii) an algorithm for automatic generation of kinematic equations, and (iii) an algorithm for automatic construction of a positional analysis procedure for solving the generated system of algebraic equations. For mechanisms containing higher-class Assur groups, the developed approach automatically generates an ordered sequence of two-link kinematic chains. When direct decomposition is not possible, conditional driving links are introduced by selecting conditionally disconnected links and defining corresponding driving coordinates. The proposed algorithms have been implemented in the SAPRM system. The applicability of the approach is demonstrated through positional analysis of three planar linkage mechanisms containing higher-class Assur groups.

Currently, robots are widely used in orthopedics for surgical operations in the world. The use of robots in orthopedics has increased the accuracy of bone cutting and im-plant placement, which has improved the results of surgical operations. Most robots used in orthopedics have a serial or parallel structural scheme. However, serial robots have low load capacity and rigidity and insufficient accuracy. The disadvantages of the parallel structural scheme of the robot are a smaller workspace and the presence of singular configurations compared to serial ones. To eliminate the above disadvantages of surgical robots for knee joint operations and to create an inexpensive robot, a hybrid Cartesian robot for knee joint surgery has been developed. The hybrid Cartesian robot has the strengths of parallel and serial robots, potentially smoothing out the main dis-advantages of their designs. The forward and reverse kinematics of the proposed robot are analyzed. A 3D model of a hybrid Cartesian robot for knee joint surgery is devel-oped and its prototype is designed in a simplified form based on it. The simplified pro-totype of a hybrid Cartesian robot for knee joint surgery provides sufficient accuracy in resection of hard bone and has good prospects for practical use.

Determining the precise position of a differential wheeled mobile robot requires further development of various sensor systems and localization methods. To achieve precise localization, odometry, which is based on measuring the angular velocity of its wheels, is primarily used. This article provides a brief overview of odometry methods and their calibration methods. A new method for calibrating a differential wheeled mobile robot using a trajectory measurement device is presented. The robot's trajectory measurement device is developed based on a high-precision rope displacement sensor and an absolute angular encoder. Using a trajectory measurement device during the calibration of a differential wheeled mobile robot facilitates data collection during experimental tests. The proposed method is compared with a differential wheeled mobile robot calibration method for correcting systematic errors along a linear path. The experiment was conducted on a MRTC differential wheeled mobile robot. The robot was calibrated using the developed method, and odometry error improvements were obtained, slightly better than those obtained using the well-known linear path calibration method. The method developed in this paper can be considered a simple and practical tool for calibrating various types of mobile robots.