Precise positioning of a robot plays an very important role in advanced industrial applications, and this paper presents a new kinematic calibration method based on the extended Kalman filter (EKF) and particle filter (PF) algorithm that can significantly improves the positioning accuracy of the robot. Kinematic and its error models of a robot are established, and its kinematic parameters are identified by using the EKF algorithm first. But the EKF algorithm has a kind of linear truncation error and it is useful for the Gauss noise system in general, so its identified accuracy will be affected for the highly nonlinear robot kinematic system with a non-Gauss noise system. The PF algorithm can solve this with non-Gauss noise and a high nonlinear problem well, but its calibration accuracy and efficiency are affected by the prior distribution of the initial values. Therefore, this paper proposes to use the calibration value of the EKF algorithm as the prior value of the PF algorithm, and then, the PF algorithm is used further to calibrate the kinematic parameters of the robot. Enough experiments have been carried out, and the experimental results validated the viability of the proposed method with the robot positioning accuracy improved significantly.

The extended Kalman filter (EKF) is a method extensively applied in many areas, particularly, in nonlinear target tracking. The optimization criterion commonly used in EKF is the celebrated minimum mean square error (MMSE) criterion, which exhibits excellent performance under Gaussian noise assumption. However, its performance may degrade dramatically when the noises are heavy tailed. To cope with this problem, this paper proposes two new nonlinear filters, namely the linear regression maximum correntropy EKF (LRMCEKF) and nonlinear regression maximum correntropy EKF (NRMCEKF), by applying the maximum correntropy criterion (MCC) rather than the MMSE criterion to EKF. In both filters, a regression model is formulated, and a fixed-point iterative algorithm is utilized to obtain the posterior estimates. The effectiveness and robustness of the proposed algorithms in target tracking are confirmed by an illustrative example.

Since space intelligent robots are not restricted by physiological conditions, it is an attractive choice for the development of automation technology to use them for space exploration and utilization. It is currently the key development direction of the major space powers over the world. This paper first investigates the robotic manipulators and humanoid robot systems for space station applications and reviews theories and methods for robots to achieve large-range stable motion and intelligent dexterous manipulation. Then, the intelligent robot systems for on-orbit satellite maintenance are reviewed, and the related technologies of multirobot collaboration are analyzed. Finally, we investigate the intelligent robot systems for on-orbit assembly of large-scale spatial structures and summarize the technologies of modular assembly and on-orbit manufacture. Overall, this paper reviews the technological progress and development trends of space robots, which provides a good reference for further technical research in this field.

Aiming at the question that most of the existing pipeline robots can only move in parts of common pipeline environments, in this study, we introduce a novel pipeline robot configuration with excellent environmental adaptability and obstacle avoidance capability for inspecting a more complex pipeline system. To ensure adaptability and mobility, the pipeline robot's general configuration was divided into three parts: the head, waist, and tail, with axisymmetric and planar symmetric structural distributions. Two active articulated joints connect the three sections of the pipeline robot, driving the head and tail to complete yaw and roll motions and allowing the pipeline robot to avoid raised obstacles and broken gaps. Furthermore, the pipeline robot can travel through annular gaps, straight pipelines with different diameters, and funnel-type pipelines due to the combination of scissor mechanism legs and a caterpillar track. Finally, a pipeline robot with the configuration and test bed with six common pipeline environments was built, and the obstacle avoidance ability and environmental adaptation experiments were conducted to evaluate the movement effectiveness. According to the experimental results, the pipeline robot can navigate smoothly within a complex pipeline environment. The pipeline robot in this setup has considerable potential in the real world.

Using robots to assist or even replace rescuers for searching and rescuing has always been a research hotspot. Robots that can carry out dexterous operations at the scene are of great significance to reduce the life threat of rescue workers. Aiming at the characteristics of narrow space and frequent physical interaction in rescue scene, a dual-arm mobile robot BIT-DMR composed of humanoid upper body and tracked mobile platform is developed in this letter. The main work is as follows: a) A high-performance lightweight and heavy payload human-machine cooperative manipulator is developed, which has a slender shape and a large flexible workspace, improving the operation ability of the robot in complex rescue environment. b) A highly integrated tracked mobile platform is developed, which can change a variety of forms leading to a high trafficability in complex terrain. The flexibility of BIT-DMR to carry out rescue operation is verified by a series of experiments like payload testing, mobile platform performance, obstacle removing, door opening and casualty rescuing. This letter provides technical reserves for robots to assist or replace human beings to carry out rescue operations at the scene.

This article proposes an effective stepwise nontransient method for entering and exiting the active short circuit (ASC) of permanent magnet synchronous motor (PMSM) to protect the safety of vehicle's drive system when fatal faults occur in the electric vehicles (EV) powertrain system with high motor speed. It is found that excessive transient current and overshoot voltage inevitably occur when ASC enters and exits directly, which may cause the demagnetization of permanent magnet and failure of motor controller unit (MCU). The two-phase short circuit is utilized as a transition step before entering and exiting three-phase ASC according to the rotor magnet position, and almost no transient current and overshoot voltage exist during the whole short-circuit period. Then, there are no constraints of ASC for system design and the system material cost can be reduced. This approach is useful for function safety implement of MCU for EV application with fast attenuation rate of transient current, high robustness, and limited resources requirement. The method with effective suppression of transient current and overshoot voltage is verified by the experimental results from a 15 kW PMSM test platform.