In multi-view clustering (MVC), complementary and consistent information from multiple views is integrated to improve clustering performance. However, inter-view sample correspondences may be partially missing in practice, making it difficult to learn cross-view consistency, which leads to the partially view-aligned problem (PVP). Most existing partially view-aligned clustering (PVC) methods first learn cross-view consistent representations based on known alignments, and then recover missing correspondences by measuring cross-view similarity between samples. However, such an indirect alignment recovery process depends on high-quality consistent representations and lacks effective utilization of known alignments, often resulting in sub-optimal outcomes. To address this, we propose a novel direct alignment recovery perspective, instantiated as K-Nearest Neighbors Direct Alignment (KNNDA). Specifically, we first construct an alignment domain by mapping the aligned neighbors of each unaligned sample into the aligned view. Then, we compute alignment confidence based on the similarity between known aligned pairs of neighbors. In particular, we use a dynamic threshold to filter out unreliable alignments. Finally, new alignments are generated within the high-confidence alignment domain. Contrastive loss is used to learn consistent representations for clustering. Comprehensive experiments on several real-world datasets show the effectiveness and superiority of our module in partially view-aligned clustering.

The inherent elasticity of soft materials can be used to create robotic grippers that deform and comply to a variety of irregular shapes. To date, several soft adaptive grasping strategies have been reported, however, most of them focus on adapting to the overall shape of the structure, while the adaptive grasping of small surface asperities is overlooked. In this paper, we propose a novel method to achieve adaptive grasping on surface asperities with a smart shape-memory silicone sponge. Heating above 60°C makes the sponge soft and deformable to allow it to penetrate within surface asperities via a pressure normal to the surface. Cooling down below 60°C makes the sponge "jam" to retain its deformed shape. The interlocking force between the jammed sponge and the asperities, and the increased area of contact, allows for adaptive grasping on asperities down to 0.4 mm with an adhesive force of up to 27.7 N in a 40 × 40 mm contacting area. We introduce the design, working principle, fabrication, and optimization of a robotic gripper based on this shape-memory silicone sponge. This sponge-jamming gripper shows great potential for developing next-generation robotic grippers for the manipulation of textured and discontinuous surfaces.

Soft devices employ variable stiffness to ensure safety and improve the robustness in the interaction between robots and objects. Using soft materials is one of the most popular approaches to design a variable-stiffness device, while the use of silicone sponge remains less explored in this field. Here we present a novel silicone-sponge-based variable-stiffness device (SVD). The SVD is easy-to-make and low-cost, and fabricated by an air-tight bellow enclosing a silicone sponge core. This allows easy access to the hyper-elastic response of the porous sponge whilst stiffness tuning of the device via pneumatic pressure difference. A detailed mathematical model of the SVD is proposed, by which the stiffness can be precisely controlled by the pressure difference applied. The stiffness of SVD can be tuned in the range of$[\mathbf{1.55}, \mathbf{2} \mathbf{2.82}]\times \mathbf{10}^{\mathbf{3}}\ \mathbf{N}/\mathbf{m}$, up to 14.7 times increase. The high stiffness is easily triggered by a low pressure difference$(\mathbf{\Delta} \boldsymbol{P} < \mathbf{12}\mathbf{kPa})$. The SVD is a versatile and compact module, with small axial size (10 mm height) and light weight (14.3 g), making it highly suitable for integration in a wide range of robotics and industrial applications. This, in addition to its easy-to-fabricate and low-cost features, may appeal to the robotics community at large. We further detail its working principle, fabrication processes, mathematical model and automated control methods to show its versatility.

Tactile sensors can be used for motion detection and object perception in robot manipulation. The contact detection within the camera's visual inspection area has been well-developed, but perception outside the field of view of the camera is overlooked. In this paper, we present a new tendon-linked tactile sensor, MechTac, to achieve perceptions inside and outside the field of view. The MechTac is an evolution of the typical TacTip sensor with the following two advantages. 1) The ability to provide perception outside the field of view. This is achieved by using a network of braided tendons to transfer deformation from the blind perception regions (TacSide) to the visual areas (TacTip). 2) The tactility of the TacSide and TacTip is reflected by the movements of multiple papillae pins and visible markers on the pin tips on the inner surface of the TacTip. The pins and markers are differentially sensitive to various touch features, which is similar to the differentiated perceptual ability of humans. TacTip is more sensitive to small touches, corresponding to the fingertip, while the TacSide is less sensitive but has a larger perceptual area, corresponding to the middle part of the finger. Moreover, we propose a new deep learning method to decompose the mixed information affected by the TacSide and the TacTip. A modified DenseNet121 was specifically designed for object perception at the TacTip and localization at the TacSide. The experimental results show that prediction accuracy reaches about 98% for object perception or localization and over 99% for the case requiring two functions.

Snails’ unique locomotion abilities help them realise stable movement by muscular exploiting travelling waves and friction modulation. Inspired by these characteristics, snaillike robots have recently become the focus of growing research. In this paper, we present a novel friction-driven three-foot snaillike robot which employs a simple mechanism to partially mimic and replicate snail-like motion, but in a novel form. This robot is driven by two servo motors, which makes it easy and low-cost to fabricate. The robot operates by breaking frictional symmetry in the cyclic motion of the three feet, in much the same way as the three-sphere Golestanian swimmer. The symmetry of its structure and properties of friction give the robot distinctive movements. We present a mathematical model of the robot’s locomotion, focusing on its kinetic harmonic-peristaltic movement. We designed and fabricated the robot, then undertook simulations and experiments, which closely match the analytic solutions. This robot provides a new approach to realising simpler and lower cost biomimetic mobile robots.