Determination of control actions and energy consumption during programmed motion of the manipulator

The paper presents the modeling of the solution to one of the problems of mechanics - the automated control of the manipulator used in the forestry industry for moving operations at various stages of the technological process. A unified model has been developed that allows generating control actions and energy consumption of the object under study. As a result of solving the problem, a system of equations was obtained for determining the control moment and control force, which allow the manipulator to be set in motion, as well as to determine the energy consumption for the implementation of the program motion, in which the load moves at a given speed from point a to point b along a straight line inclined at a given angle to the horizon. The proposed algorithm is generalized for solving computer-aided design problems and is a simulation experiment. The software solution is implemented in two forms. In the first module, the database is filled with the initial metric, angular and physical and mathematical characteristics of the manipulator. In the second, according to the unified model described above, the indicators are calculated that are necessary for the movement of the object and characterize the dynamics of movement, as well as the necessary energy consumption for performing the operations performed. The possibility of converting the calculated values from the database into an MS Excel table is provided.

Pose Measurement and Assembly of Spacecraft Components based on Assembly Features and a Consistent Coordinate System

To assemble spacecraft automatically and precisely, it is vital to measure the relative spatial pose (position and orientation) of the assembly features of the spacecraft components before assembly. For large-scale spacecraft components, the global measurement method is mainly utilized to guide assembly control, and its accuracy and efficiency have ultimately failed to meet requirements. To address this issue, a novel measurement method is proposed. Since the goal is to measure the relative spatial pose of the assembly features of the spacecraft components, the proposed method measures it directly to ensure the consistency of the measurement and assembly coordinate system. This method has the advantage of high precision because it can reduce the influence of structural parameter errors and is not limited by the scale of the spacecraft components. In addition, it requires only one offline calibration, which significantly improves the efficiency of online measurement and assembly. Taking the control moment gyroscope (CMG) assembly task as an example, a measurement system and its corresponding calibration device are designed and developed. After calibration by the calibration device, the measurement system is mounted on the assembly features of the CMG to measure the relative spatial pose between the assembly features of the CMG and the assembly features of the mounted base (MB). Finally, six assembly experiments are completed according to the measurement results. The experimental results show that this method has high accuracy and can guide the robot to achieve high assembly accuracy, satisfying the assembly requirements of typical spacecraft components.

Air-Launch Experiment Using Suspended Rail Launcher for Rockoon

The method of air-launching a rocket using a launcher suspended from a balloon, referred to as a rockoon, can improve the flight performance of small rockets. However, there have been safety issues and flight trajectory errors due to uncertainty with respect to the launch direction. Air-launch experiments were performed to demonstrate a rail launcher equipped with a control moment gyroscope to actively control the azimuth angle. As a preliminary study, it was suspended via a crane instead of a balloon. The rockets successfully flew along the target azimuth line and impacted the predicted safe area. The elevation angle of the launcher rail exhibited a fluctuation composed of two frequency components. A double-pendulum model with a rigid rod suspended by a wire was proposed to predict this behavior. Significant design parameters and error sources were investigated using this model, revealing the constraining effect of a large mass above the wire and elevation angle fluctuation, which caused trajectory errors due to the friction force on the rail guide and thrust misalignment. Finally, tradeoffs in designing the rail length were found between the launcher clear velocity and elevation fluctuations.

A Gimballed Control Moment Gyroscope Cluster Design for Spacecraft Attitude Control

This paper addresses the problem of singularity avoidance in a cluster of four Single-Gimbal Control Moment Gyroscopes (SGCMGs) in a pyramid configuration when used for the attitude control of a satellite by introducing a new gimballed control moment gyroscope (GCMG) cluster scheme. Four SGCMGs were used in a pyramid configuration, along with an additional small and simple stepper motor that was used to gimbal the full cluster around its vertical (z) axis. Contrary to the use of four variable-speed control moment gyroscopes (VSCMGs), where eight degrees of freedom are available for singularity avoidance, the proposed GCMG design uses only five degrees of freedom (DoFs), and a modified steering law was designed for the new setup. The proposed design offers the advantages of SGCMGs, such as a low weight, size, and reduced complexity, with the additional benefit of overcoming the internal elliptic singularities, which create a minor attitude error. A comparison with the four-VSCMG cluster was conducted through numerical simulations, and the results indicated that the GCMG design was considerably more efficient in terms of power while achieving a better gimbal configuration at the end of the simulation, which is essential when it is desired for different manoeuvres to be consecutively executed. Additionally, for a nano-satellite of a few kilograms, the results prove that it is feasible to manufacture the GCMG concept by using affordable and lightweight commercial off-the-shelf (COTS) stepper motors.

Gyroscopic Stabilization of Two Wheeled Electric Vehicle

This paper report on research and fabrication of an electric vehicle prototype that will be capable of balancing itself without human effort. This vehicle will be implementing a control moment gyroscope for balancing purpose. The project also concerned about the environmental effects of conventional internal combustion Engines and to effectively use the alternative propulsion system which is electric traction system, where using Electric motors the vehicle is propelled. The system uses a control moment gyroscope to static balancing of the vehicle and using its angular momentum and precessional moment. Along with the fact that it uses a electric traction motor he implementation of new optimizations for power and mileage the efficiency is improved.