High-dynamic tactile sensing and tactile servo control present challenges in robustness and real-time performance. This paper proposes a closed-loop tactile servo control strategy for robotic nail hammering, by allowing controlled hammer slide within a rigid robotic 2-finger gripper. The proposed approach detects tactile information of continuous sliding and sliding-induced vibrations in real time and modulates gripping force. The control encourages rotational sliding to enhance impact and reduce recoil while restricting parallel slippage to maintain grip stability. To achieve real-time processing and effective sliding feature extraction, we employ Short-Time Fourier Transform (STFT) and a dual-stream Physics-Informed Machine Learning (PIML) model, processing tactile data at 1 kHz with an average latency of 1.04 ms. Experimental results show that, compared to conventional methods, controlling hammer slippage reduces arm joint recoil by 64.26% (223.30 N → 79.81 N) while increasing hammer impact force by 179.97% (28.06 N → 78.56 N). The method adapts to hammers with varying mass distributions, significantly improving impact resilience and manipulation performance in high-dynamic interactions. These advancements pave the way for more dexterous and robust robotic systems with embodied intelligence.

With recent advancements in CV (computer vision) and AI (Artificial Intelligence) technologies, pointing gesture is becoming an emerging trend for human-robot interaction. Its intuitive and deictic nature makes it an ideal way for giving commands, especially referring spatial information to the robots. In this paper, we propose an augmented pointing gesture estimation method to enable richer and programmable instructions to be given to the robots. We propose five pointing gestures and demonstrate the idea using a collaborative robot with a multi-finger robotic gripper. Experiments are designed and conducted to test the pointing accuracy in space and in gesture estimation. The results show that our proposed method can achieve a mean drift of 8.3 cm and an estimation accuracy of 94.08%.

This paper presents CCRobot-V, the fifth version of CCRobot, a cooperative serial multi-robot system for bridge cable inspection and maintenance that uses silkworm-like locomotion to climb the entire length of super-long stay cable at high speeds while carrying heavy inspection/maintenance equipment. CCRobot-V consists of one climbing precursor robot, one inspection/maintenance robot, several cable-carrying robots, and a power-tethered cable guiding system. The pre-cursor robot is the “head,” which leads the affiliated sub-robots along the bridge cable. Every sub-robot possesses a pair of self-locking palms. When a sub-robot grips on the bridge cable with its palms, it becomes a fixed anchor point that allows the adjacent sub-robots in front and back to use winches and steel wires to pull themselves upward. With this cooperative multi-robot system, cable inspection/maintenance tasks can be divided into several functional units, with each inspection/maintenance equipment installed separately on a customized sub-robot. Thus, CCRobot-V provides a complete mobile inspection/maintenance work line for a bridge cable. The experimental and field tests demonstrate CCRobot-V's high climbing speed, high payload capacity, and full-length cable moving capability. It has the potential application value for the actual bridge cable inspection/maintenance.

In DC microgrid, it is common that constant power loads (CPLs) exhibit negative impedance characteristics, which degrades the stability margin of the whole system. This paper focuses on the stability problem of isolated DC microgrid with multiple DC voltage control units and constant power loads. Taking controllers into account, the detailed impedance model of DC microgrid is established, and it shows the interaction between converters through analyzing the minor loop gain by using Nyquist criterion. Meanwhile, resonance is examined using impedance model. Impedances-based stability analysis reveals the influence of different factors on the stability, such as the size of the CPLs and the droop coefficient. To verify the analysis results, the simulation model is built based on PSCAD/EMTDC. The simulation results confirm the validity of the method. With the developed dc impedance and stability analysis method, the DC microgrid system stability characteristics can be evaluated, which can be used for system design to maintain stability.