One of the technologies used for localization is GNSS (Global Navigation Satellite Systems), which is exposed to many phenomena, i.e., the occurrence of terrain covers, reflections of the radio waves, and the multipath nature of the radio waves in the propagation environment. To increase the resistance to environmental phenomena, special types of antennas are used, which include, among others, choke ring antennas. The article describes the design and construction of the choke ring antenna and the impact of the mentioned device on the quality of GNSS positioning. The accuracy of the constructed antenna (based on selected accuracy measures: DRMS, 2DRMS, SEP, MRSE, SAE) is calculated together with positioning errors determined for two types of antennas: choke ring antenna and the dedicated antenna supplied by the manufacturer in RTK mode. The results confirm that the designed choke ring antenna can be used for positioning without significantly losing accuracy in the RTK mode.
Many fields, where human health and life are at risk, are increasingly utilizing mobile robots and UGVs (Unmanned Ground Vehicles). They typically operate in teleoperation mode (control based on the projected image, outside the operator’s direct field of view), as autonomy is not yet sufficiently developed and key decisions should be made by the man. Fast and effective decision making requires a high level of situational and action awareness. It relies primarily on visualizing the robot’s surroundings and end effectors using cameras and displays. This study aims to compare the effectiveness of three solutions of robot area imaging systems using the simultaneous transmission of images from three cameras while driving a UGV in complex terrain.
The following paper describes research on the influence of hydraulic accumulator parameters on the efficiency of energy recovery for a simulation model of a wheel loader using the results of experimental research. A design solution for the energy recovery system for the loader attachment was presented, which allows for the recovery of the potential energy of the boom, bucket, and load. The presented simulation model was developed based on a real object. The necessary operating parameters were determined using experimental tests. The study used the co-simulation method of mechanical and hydraulic models in order to more accurately reflect the actual behavior of the research object. The validated simulation model was extended with the developed energy recovery module based on a hydraulic accumulator. The results of the conducted tests have indicated the influence of hydraulic accumulator parameters on the efficiency of energy recovery and potential directions for further research.
The article explored the potential for enhancing the off-road mobility of unmanned ground vehicles (UGV) equipped with a hydrostatic drive system. The analysis showed that effectively overcoming rough or soft terrain demands a slip limitation. In the UGVs with hydrostatic drives, flow dividers are used for this purpose. Unfortunately, they have certain drawbacks, such as reduced efficiency due to pressure losses. In order to minimize this phenomenon, an external braking system was used as a new slip control system. Therefore, simulation studies were carried out to assess the new slip control system while overcoming terrain obstacles due to the reduction of energy consumption and improving the mobility of the UGV.
More and more commonly, manipulators and robots equipped with effectors are used to replace humans in the implementation of tasks that require significant working abilities or are used in dangerous zones. These constructions have considerable ranges and are capable of carrying heavy loads. The specificity of the tasks performed with the use of mentioned devices requires their control by a human. Intuitive tracking systems are used to control them. Problems in their use result from the kinematic amplification between the effector and the operator’s hand. Proper design of the drive and control systems for these manipulators requires knowledge of the maximum velocities of the manipulator’s effectors, which significantly depend on the scale ratio. The article presents the results of the effector’s velocity movements while performing a specific task by the operator’s hand with different velocities and scale ratios.
25 April 2018 in Challenges to national defence in contemporary geopolitical situation
In contemporary conflicts the IED and mines threats are growing. In paper the concept of using engineer robots in counter IED operation are described. To fulfil this analyses the cooperation between varied class robots are proposed.