It is necessary to upgrade and transform the sorting equipment in the industrial production line. In order to improve production efficiency and reduce labor intensity, a high-speed lightweight parallel mechanism control system for the high-speed sorting and packaging of light items was studied. A fuzzy PID controller based on genetic algorithm (GA) optimization is proposed according to the nonlinear and strong coupling characteristics of the parallel mechanism (PM) control system. The inverse kinematic analysis was conducted to map the workspace trajectory tracking problem to the joint space. It was transformed into the trajectory planning and solving problems in the joint space. The motion trajectory was obtained utilizing quintic polynomial interpolation. Finally, the servo control system model was established, and the PID control parameters were optimized and self-tuned by the GA. They were applied to the fuzzy PID controller for simulation experiments. The simulation results showed that the GA-optimized fuzzy PID control system compared with the fuzzy PID control system had a 23.39% shorter rise time, 22.32% less regulation time, and 7.18% less steady-state error. The control system had a good dynamic and steady-state performance.

Reverse design and tests of vegetable plug seedling pick-up mechanism of planetary gear train with non-circular gears

Room-temperature liquid-metal (LM) has high conductivity, which is an ideal material for manufacturing stretchable electronic wires. However, its high surface tension and fluidity make it extremely difficult to adhere to or encapsulate on flexible substrates. This work developed LM/NdFeB/Ni composites for stretchable electronic wires. The composites were composed of Ga68.5In21.5Sn10 (with a melting point at −19 °C) alloys, Nd2Fe14B (5 μm), and Ni (50–500 nm) microparticles. The SEM and EDS results showed the porous structure of the composites. Ni particles were added to improve the magnetic properties of LM/NdFeB composites, as well as the porous structure composed of magnetized NdFeB particles. Thereby the structure exhibited a heightened capacity for LM locking. Test results indicate that the liquid metal wires have good wettability and adhesion on different surfaces and could be manufactured using different patterning methods. Moreover, its anti-extrusion and anti-leakage characteristics were suitable for constructing stretchable circuits in open channels or on flat surfaces. The proposed LM/NdFeB/Ni composites are expected to manufacture low-cost, patternable, and anti-extrusion stretchable electronic wires.

Contactors are extensively utilized in the control field. Enhancing the response speed and reducing mechanical tremors during switching-in hold great significance in improving contactor’s reliability. A novel A.C. contactor suitable for low-voltage environments has been developed based on the unique properties of the magnetic shape memory alloy (MSMA). It exhibited remarkable characteristics such as large dependent variables, fast response speed, and strong controllability. First, the magnetron characteristics of the MSMA were introduced. Then, the overall structure of the new contactor was designed based on the MSMA output characteristics and the contactor’s design requirements. Next, switching-in characteristics of the contactor under the drive signal were analyzed through simulation. Finally, an experimental measurement was carried out to test the performance of the prototype contactor during separating brake and switching in. The A.C. contactor driven by the MSMA could achieve a response speed of 9.8 ms. The contact movement in the switching process is smooth, which effectively avoids the occurrence of contact bounce in the closing process, which provides theoretical support for the development of the MSMA in the field of low-voltage electrical control application research.

This work presents a recyclable liquid-metal/NdFeB composite magnet (LM magnet) with a reconfigurable shape and polarity. Taking advantage of the low-temperature phase-transition property of LMs, we can re-orient the NdFeB particles and reshape the LM magnets, to produce complex magnetization profiles or complex structured magnets. The manufacturing of LM magnets was realized at low temperatures by using a template and paired permanent magnets. The microscopic morphology and elemental composition of the LM magnet were analyzed by scanning electron microscopy and energy dispersive spectroscopy, respectively. The magnetic properties and phase-transition properties of the LM magnet were analyzed using a vibrating sample magnetometer (VSM) and a differential scanning calorimeter. The experimental results verified that the LM magnet can be recycled, reconfigured, and welded. The configurable magnetization profile with a resolution of up to 800 µm demonstrates that manufacturing of complex magnetic poles can be achieved through this technique. Finally, three application cases show the application prospects of the LM magnet in robots and sensors.