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h i g h l i g h t s• Proposes a layout for a walking free-leg hexapod machine tool. • Optimisation approach for tripod gait based on selected system parameters.• Proposes an algorithm for independent walking motion based on stability. a b s t r a c tThe scope of this paper is to present a novel gait methodology in order to obtain an efficient walking capability for an original walking free-leg hexapod structure (WalkingHex) of tri-radial symmetry. Torque in the upper (actuated) spherical joints and stability margin analyses are obtained based on a constraintdriven gait generator. Therefore, the kinematic information of foot pose and angular orientation of the platform are considered as important variables along with the effect that they can produce in different gait cycles. The torque analysis is studied to determine the motor torque requirements for each step of the gait so that the robotic structure yields a stable and achievable pose. In this way, the analysis of torque permits the selection of an optimal gait based on stability margin criteria. Consequently, a gait generating algorithm is proposed for different types of terrain such as flat, ramp or stepped surfaces.

The scope of this paper is to present a novel method of actuating the legs of a walking parallel kinematic machine tool (WalkingHex)

Although Global Navigation Satellite Systems (GNSSs) generally provide adequate accuracy for outdoor localization, this is not the case for indoor environments, due to signal obstruction. Therefore, a self-contained localization scheme is beneficial under such circumstances. Modern sensors and algorithms endow moving robots with the capability to perceive their environment, and enable the deployment of novel localization schemes, such as odometry, or Simultaneous Localization and Mapping (SLAM). The former focuses on incremental localization, while the latter stores an interpretable map of the environment concurrently. In this context, this paper conducts a comprehensive review of sensor modalities, including Inertial Measurement Units (IMUs), Light Detection and Ranging (LiDAR), radio detection and ranging (radar), and cameras, as well as applications of polymers in these sensors, for indoor odometry. Furthermore, analysis and discussion of the algorithms and the fusion frameworks for pose estimation and odometry with these sensors are performed. Therefore, this paper straightens the pathway of indoor odometry from principle to application. Finally, some future prospects are discussed.

Small punch testing exhibits great potential in mechanical characterisation of thin coatings.This testing method can be used to determine the mechanical performance of thermally sprayed coatings, especially to qualitatively characterise the effects of coating defects on the mechanical behaviour. In this work, some considerations in using the small punch testing for coatings are presented through a microstructure evolution analysis of a vacuum plasma sprayed CoNiCrAlY coating under small punch test. The CoNiCrAlY coating was characterised with a large number of un-melted particles as the coating defects. It is shown that the clamping in the small punch test rig can result in micro-cracking around the unmelted particles in the coating prior to testing. It is also found that the un-melted particles in the coating act as predominant cracking sites and fast failure occurred around the un-melted particles. Careful considerations need to be taken into account when using the small punch test for coatings to avoid any changes in the coating microstructure and plasticity during the clamping stage.