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The purpose of this paper is to present a new scout robot that tries to combine the hopping movement and the wheeling movement to greatly enlarge the scope of robot's activities.

A five‐shank hopping mechanism was employed to build the wheeling‐hopping combination scout robot. The non‐linear character of the five‐shank hopping mechanism was analyzed and then used in the proposed non‐linear spring‐mass model for the robot.

The rules of robot's movement were deduced, influencing factors of the jumping height were analyzed and the countermeasure was adopted. Simulations and an experiment of the robot's movement showed that the robot has strong locomotivity and survival ability.

A five‐shank hopping mechanism is proposed, analyzed and combined with wheeling movement to enhance the locomotivity and survival ability of scout robot.

There is explosive gas in many disaster environments. The conventional search and rescue robots are not allowed to work in these environments, since they may cause explosion. The purpose of this paper is to describe the design and development of the serpentine omnitread robot HITSR‐I for working in these areas.

HITSR‐I consists of four segments, and each segment is equipped with crawlers in the four directions. It can be operated even under the situation of sideslip without any recovering actions. There are pressed CO₂ containers and the pressurized control system inside the robot, and the shells of the robot are a fully sealed up structure. They can maintain the inside pressure higher than the outside. The robot can release the communication relay node to extend the communicating area, so it can search a large area even amid rubble.

HITSR‐I was developed with the capability of climbing over 400 mm high obstacles. The maximum travel distance was 315 m. The pressurized system could enable the robot to work in Zones 1 and 2.

Design and development of a serpentine robot which can work in hazardous areas containing explosive gas. It can travel for a long distance in ruins by releasing the communication relay nodes.

The purpose of this paper is to achieve high-precision sliding mode control without chattering; the control parameters are easy to adjust, and the entire controller is easy to use in engineering practice.

Using double sliding mode surfaces, the gain of the control signal can be adjusted adaptively according to the error signal. A kind of sliding mode controller without chattering is designed and applied to the control of ultrasonic motors.

The results show that for a position signal with a tracking amplitude of 35 mm, the traditional sliding mode control method has a maximum tracking error of 0.3326 mm under the premise of small chattering; the boundary layer sliding mode control method has a maximum tracking error of 0.3927 mm without chattering, and the maximum tracking error of continuous switching adaptive sliding mode control is 0.1589 mm, and there is no chattering. Under the same control parameters, after adding a load of 0.5 kg, the maximum tracking errors of the traditional sliding mode control method, the boundary layer sliding mode control method and the continuous switching adaptive sliding mode control are 0.4292 mm, 0.5111 mm and 0.1848 mm, respectively.

The proposed method not only switches continuously, but also the amplitude of the switching signal is adaptive, while maintaining the robustness of the conventional sliding mode control method, which has strong engineering application value.

The assembly quality of complex products is pivotal to their lifecycle performance. Assembly precision analysis (APA) is an effective method used to check the feasibility and quality of assembly. However, there is still a need for a systematic approach to be developed for APA of kinematic mechanisms. To achieve more accurate analysis of kinematic assembly, this paper aims to propose a precision analysis method based on equivalence of the deviation source.

A unified deviation vector representation model is adopted by considering dimension deviation, geometric deviation, joint clearance and assembly deformation. Then, vector loops and vector equations are constructed, according to joint type and deviation propagation path. A combined method, using deviation accumulation and sensitivity modeling, is applied to solve the kinematic APA of complex products.

When using the presented method, geometric form deviation, joint clearance and assembly deformation are considered selectively during tolerance modeling. In particular, the proposed virtual link model and its orientation angle are developed to determine joint deviation. Finally, vector loops and vector equations are modeled to express deviation accumulation.

The proposed method provides a new means for the APA of complex products, considering joint clearance and assembly deformation while improving the accuracy of APA, as much as possible.