Aiming at the defects of long axial size and low torque density of the existing radial flux permanent magnet motor, this paper proposes an axial flux permanent magnet synchronous motor (AFPMM) with a double-stator and single-rotor structure based on the design requirements of the motor for mechanical dogs’ electric drive joints. The finite element method is employed to evaluate the static magnetic field, load characteristics, and associated losses. The analysis indicates that the average magnetic flux density in the air gap reaches approximately 0.95 T, with a rated torque of around 2.72 N.m, a peak torque of 7.6 N.m, and an efficiency of approximately 87.73%. The electromagnetic torque model is developed using the Maxwell tensor method, allowing for the effects of critical structural parameters on torque to be investigated. By optimizing the design for torque density, an improvement of nearly 20% is achieved. A prototype was fabricated and tested, demonstrating good agreement between simulation and experimental results. This research introduces a novel approach for designing axial flux motors with high torque and power densities.

The launch method of one arrow with multiple satellites can greatly shorten the time for constellation networking and improve the deployment efficiency. A new compression and separation device with a four-bar perimeter arrangement is proposed for multi-satellite compaction and in-orbit release. A compression device with gap elimination is designed to implement the reliable compaction of stacked flat satellites. An electromagnetic separation device is proposed to achieve the fast, low-interference release of multi-satellites. The dynamic model with flexible guide bars is established. The separation characteristics of multiple satellites are analyzed by the kinematic simulation. The prototype is developed, and the related experiment is implemented. The results show that the four-guide-bar-edge arrangement scheme with a gap elimination device achieves reliable locking and fast separation under a vibration environment. The dynamic separation characteristics of satellites are investigated by the air floatation experiments. The results show that a stable separation speed and low disturbance angular velocity are achieved under 10% spring error.

In-orbit docking technology of microsatellites to realize combined reconfiguration has a wide application prospect, such as large antennas and space telescopes. In order to reduce collision impact and improve docking accuracy, a new deployable docking mechanism is proposed based on the slider-crank principle, which has the advantages of smaller volume and larger posture tolerance. To achieve large capture tolerance and increase the success rate of docking, the posture error is analyzed by considering the specific boundary of the position and pose. And a step-by-step cooperative capture strategy is proposed to complete the velocity selection and action matching among multiple capture arms. The reliable docking of posture correction in the docking process is realized by designing the action path of the docking mechanism. The effects of tolerance capture under different initial posture conditions are analyzed by dynamic simulation. The effectiveness and superiority of the step-by-step cooperative capture strategy are valid by comparison with the synchronized capture strategy. The comparison results show that the impact force is reduced by 8% than the synchronized strategy. The capture experiments are carried out to verify the docking performance. The results show the proposed configuration with a step-by-step cooperative capture strategy achieves successfully reliable capture, weak impact, and large posture tolerance under eight extreme initial pose conditions.

More and more CubeSats cooperate to implement complex space exploration missions. In order to store and deploy more CubeSats in a rocket-launch mission, this paper presents a new CubeSat deployer with large-capacity storage. Different from the traditional one with the compression springs, the deployer with electromagnetic actuators is proposed to achieve the transportation and release. A new electromagnetic actuator with high thrust density was applied to adjust the release speeds of the CubeSats with different masses, and a new electromagnetic convey platform with attractive force was designed to transfer the stacked CubeSats to the release window. The equivalent magnetic circuit method was used to the establish electromagnetic force models. The simplified dynamic models of the transportation and release were built. The magnetic field, electromagnetic force, and motion characteristics were analyzed. The prototype was developed to verify the performance of the proposed configuration of the deployer with electromagnetic actuators. The experimental results show that stacked CubeSats can be transported smoothly even under constant external interference. The launcher achieved high thrust density and effectively adjusted the separation speed of the CubeSats.

With the background of on-orbit repetitive connection and separation of CubeSats, an electromagnetic docking mechanism for repeated docking and separation is proposed. A reusable electromagnetic docking scheme combining lead screw transmission with electromagnets is introduced. The electromagnetic force/torque model and the attitude model of the CubeSat are derived based on the relationship between force and magnetic flux density in a magnetic field. The coil layout and the polarity of magnetic poles are optimized and analyzed, four different layout configurations are proposed, and their mechanical characteristics are analyzed. A multi-body dynamics simulation analysis of the entire mechanism is conducted to evaluate the attitude correction capability of the electromagnetic attraction separation unit. A three-degrees-of-freedom capture and separation test of the electromagnetic attraction separation unit is carried out in a microgravity-simulated environment to investigate the characteristics of capture and separation under different position and attitude deviation conditions of the energized solenoids. The designed electromagnetic docking mechanism has an adaptive attitude adjustment and docking range of a 30° cone. It can achieve low-impact, high-tolerance, and reusable docking and separation.

The deployment performance of the unfolded wing determines whether the winged missiles can fly normally after being launched, infecting the attack performance of the winged missiles. The paper proposes a new deployment mechanism with clearance eliminator. Based on the slider-crank principle, the proposed deployment mechanism achieves fast and low-impact deployment of the wings. The proposed clearance eliminator with shape memory alloy (SMA) effectively eliminates the clearance of the sliding pair and improves the support stiffness and stability of the deployed wing. The collision characteristics and the clearance elimination are studied for the deployment mechanism. The influence of the collision force on the motion state of the wing during the deployment is analyzed. The static stiffness of the wing under the clearance state and the deformation is analyzed. The dynamic stiffness under the catapult clearance elimination state is modeled based on the fractal geometry and contact stress theory. The relationship between the locking force and the support stiffness is revealed. The kinetic simulation is used to analyze the motion response during the action of the deployment mechanism. Modal analysis, harmonic response analysis, and random vibration analysis were conducted for the whole wings. A prototype was developed to verify the ejection performance of the wing according to the input load characteristics. The dynamic stiffness of the unfolded wings is tested by the fundamental frequency experiments to verify the performance of the clearance elimination assembly. The experimental results show that the designed deployment mechanism with clearance compensation achieves fast ejection and high stiffness retention of the missile wing.