This article presents a system for the autonomous operation of a manipulator of a mobile robot. The aim of the research was to develop a system for a robot to operate a panel with switches. The manipulator should position itself autonomously and perform a given action. The operation of the system is based solely on one digital camera. The vision system uses markers to identify the position of the end-effector. The test results show that the system operates well in good artificial and natural lighting conditions. The system can be used effectively for activities that do not require high accuracy, e.g., pressing buttons and switches or grasping objects. However, for high-precision tasks, such as inserting a plug into a socket, or tasks that require high positioning accuracy, the manipulator may not be suitable.

EPJ Web of Conferences, open-access proceedings in physics and astronomy

Autonomous mobile vehicles need advanced systems to determine their exact position in a certain coordinate system. For this purpose, the GPS and the vision system are the most often used. These systems have some disadvantages, for example, the GPS signal is unavailable in rooms and may be inaccurate, while the vision system is strongly dependent on the intensity of the recorded light. This paper assumes that the primary system for determining the position of the vehicle is wheel odometry joined with an IMU (Internal Measurement Unit) sensor, which task is to calculate all changes in the robot orientations, such as yaw rate. However, using only the results coming from the wheels system provides additive measurement error, which is most often the result of the wheels slippage and the IMU sensor drift. In the presented work, this error is reduced by using a vision system that constantly measures vehicle distances to markers located in its space. Additionally, the paper describes the fusion of signals from the vision system and the wheels odometry. Studies related to the positioning accuracy of the vehicle with both the vision system turned on and off are presented. The laboratory averaged positioning accuracy result was reduced from 0.32 m to 0.13 m, with ensuring that the vehicle wheels did not experience slippage. The paper also describes the performance of the system during a real track driven, where the assumption was not to use the GPS geolocation system. In this case, the vision system assisted in the vehicle positioning and an accuracy of 0.2 m was achieved at the control points.

This article is a continuation of research on the possibility of using artificial pneumatic muscles to drive a parallel manipulator with six degrees of freedom. The authors present an artificial pneumatic muscle they have developed. The article contains a description of the research methodology and a description of the authors’ research position. The article presents the results of a comparison of the developed pneumatic muscle with an existing commercial solution. Then, the dynamic characteristics of the authors’ muscle are presented. A mathematical model is proposed that contains two inputs—the force generated by the muscle and the position of the muscle—and one output—the value of the signal controlling the pressure valve. The results of verification of the developed model are presented. The model is then presented in two versions. The first one contains the full dynamic model. The second one is its simplified version: the static model. The authors compare both models and present the comparison results. A servo drive is then synthesized and consists of a pair of muscles capable of generating the desired angular position and intended to drive a single arm of a parallel manipulator. The developed servo drive is verified on a test stand, and its behavior is assessed and analyzed in the context of its use in the manipulator.

This paper presents the design, implementation, and experimental results of a six-degree-of-freedom Delta-type parallel manipulator, in which all actuators were realized using proprietary pneumatic muscles. The objective of the study was to evaluate the suitability of this type of actuator for applications in parallel robotics, with particular attention to their dynamic properties, nonlinearities, and potential limitations. In the first part of the article, the details of the manipulator’s construction and the kinematic model, covering both the forward and inverse kinematics, are presented. The control system was based on antagonistic pairs of pneumatic muscles forming servo drives responsible for the motion of individual arms. The experimental investigations were focused on analyzing trajectory-tracking accuracy and positioning repeatability, both in unloaded conditions and under additional payload applied to the end-effector. The results indicate that positioning errors for simple trajectories were generally below 1 mm, whereas for complex trajectories and under load, they increased, particularly during changes in motion direction, which can be attributed to friction and hysteresis phenomena in the muscles. Repeatability tests confirmed the ability of the manipulator to repeatedly reach the desired positions with small deviations. The analysis carried out confirms that pneumatic muscles can be effectively applied to drive parallel manipulators, offering advantageous features such as high power density and low mass. At the same time, the need for further research on nonlinearity compensation and durability enhancement was demonstrated.