In this paper, a variable structure pneumatic soft robot is proposed. Its structure is variable in that when it grasps irregular objects, it can adapt to different sizes by active expansion or contraction. Its expansion range is from diameter 200 to 300 mm, its four soft pneumatic actuators (SPAs) can be rotated independently to adapt to different shapes, and it has high flexibility. The active compliant grasping method enables it to capture at the best position, which can improve the success rate of capture and reduce damage to the object being grasped. The experiment proves the effectiveness of the variable structure mechanism, and the proposed soft robot has low cost and a simple manufacturing process, so the mechanism has great application prospects.

Soft robots have the characteristics of good adaptability to an environment. But at present, most soft robots only complete a single specific task, and as a result, their ability to adapt to complex environments is limited. In order to solve the weak ability of soft robots to adapt to complex and diverse environments, this paper presents a new bionic omnidirectional bending actuator (BOBA) inspired by leeches, caterpillars, and other mollusks. BOBA has less radial expansion, fast response, good flexibility, and omnidirectional bending. Using modular methods, it can be quickly assembled into a soft robot with a variety of motion modes. Experiments show the multimodal soft robot can climb vertical walls, transition from one surface to another, climb stairs, leap obstacles, cross narrow pipes, and move with heavy objects. This greatly improves the ability of soft robots to adapt to complex and diverse environments.

Advancements in science and technology have driven the growing use of robots in daily life, with Portable-Powered Lower Limb Exoskeletons (PPLLEs) emerging as a key innovation. The selection of mechanisms, control strategies, and sensors directly influences the overall performance of the exoskeletons, making it a crucial consideration for research and development. This review examines the current state of PPLLE research, focusing on the aspects of mechanisms, control strategies, and sensors. We discuss the current research status of various technologies, their technological compatibility, and respective benefits comprehensively. Key findings highlight effective designs and strategies, as well as future challenges and opportunities. Finally, we summarize the overall status of PPLLE research and attempt to shed light on the future potential directions of research and development.

As an important part of the quadruped robot, the leg determines its performance. Flexible legs or flexible joints aid in the buffering and adaptability of robots. At present, most flexible quadruped robots only have two-dimensional flexibility or use complex parallel structures to achieve three-dimensional flexibility. This research will propose a new type of three-dimensional flexible structure. This passive compliant three-dimensional flexibility reduces the weight and complex structure of the robot. The anti-impact performance of the robot is verified by a side impact experiment. The simulation and experiments show that the robot still has good stability even under a simple algorithm and that the flexible leg can reduce the impact on the quadruped robot and improve the environmental adaptability of the robot.

In order to improve the speed tracking accuracy of Brushless DC motor, this paper proposes a PID control method based on deep deterministic policy gradient algorithm(DDPG) compensation. The running state of BLDCM is monitored by DDPG, and the proportional, integral and differential links of PID are compensated to make PID controller have learning ability. At the same time, the Gauss function and the maximum critical speed interval are combined to define the reward function to enhance the versatility of the control strategy. Simulation results show that the proposed strategy has better speed tracking accuracy than PID controller.

In this paper, a soft robot driven by a gas–liquid phase transition actuator with a new structure is designed; The soft robot is driven by the pressure generated by electrically induced ethanol phase transition. The gas–liquid phase transition drive was found to be able to generate a larger driving force by using only low voltage. Compared with the gas drive of a traditional soft robot, gas–liquid phase transition-driven soft robot does not require a complex circuit system and a huge external energy supply air pump, making its overall structure more compact. At the same time, because of the new structure of the actuator on the soft robot, the soft robot has good gas tightness and less recovery time. A reinforcement depth learning control strategy is also added so that the soft robot with this actuator could better grip objects of different sizes and weights.