IROS 2024 论文列表

In laparoscopic surgery, large organs are difficult to handle with one forceps, resulting in low surgical efficiency. In this study, to improve surgical efficiency, we developed a five-fingered robotic forceps that can be inserted through small incisions and has multiple degrees of freedom to handle large organs. The results of an experiment simulating sigmoidectomy showed that the proposed robotic forceps could shorten the surgical time. In addition, we confirmed that the physical burden while using the instrument was comparable to that of conventional forceps.

In this study, we propose a peristaltic flexible transfer system for transferring feces in a free piping route. Currently, human feces is incinerated and disposed in space, such as on the International Space Station. As feces contain a large amount of reusable organic matter and water, the ability to recycle feces will improve the performance of manned space technology. However, existing space toilets are not designed to reuse feces, and the transportation of feces from the toilet bowl to the collection area is a technical challenge. A method for transporting intermittent supplies such as feces with less energy and water consumption is required. In a previous study, a peristaltic transfer system was developed based on the peristalsis of the intestinal tract of living organisms. In this method, multiple pump units driven by low air pressure generate peristaltic motion, which enables horizontal, vertical, and curved transfer of simulated feces. However, because the frame of each unit is rigid, the transport path cannot be changed flexibly, and the design must be adapted to the installation location. Therefore, the frame must be flexible.We propose a peristaltic flexible transfer system for transferring feces in a free piping route. First, we construct a simple model of content transfer using the peristaltic flexible transfer system and calculate the transfer rate based on data obtained from basic characteristic experiments of a single unit. Then, we conduct an actual content transfer experiment using the transfer system and compare the results with the simplified model results.

In this study, a throwing robot equipped with an shock absorbing structure, utilizing paired-Cross Flexural Hinge (p-CFH) and an airbag, was fabricated and validated to assess the effectiveness of its impact absorption mechanism. This robot was developed in anticipation of situations where direct human intervention for life rescue would be challenging. Throwing robots can be broadly categorized into ball type, wheel type, and hybrid type. The hybrid type combines the advantages of both: the ease of throwing from ball type, due to its low air resistance coefficient, and the versatile mobility of the wheel type in diverse environments. However, hybrid type throwing robots are more vulnerable to external impacts due to the complexity of their internal structure, resulting in a lower maximum drop height compared to wheel type robots.To address these challenges, this research proposes a the Throwbot that combines the easy throwing capability of ball type with the obstacle overcoming ability of the wheel type, while also addressing the low free fall height drawback inherent in hybrid types. To achieve this, we developed a Throwbot with a ball to wheel transform structure, p-CFH mechanism, and airbag based impact absorption system. Additionally, materials were selected based on simulation results to refine the Throw-bot. The performance of the proposed robot was evaluated through various assessments, including free fall experiments and obstacle overcoming tests. Through this research, the proposed Throwbot effectively addresses the shortcomings of existing throwing robots, establishing a novel approach to throwing robot design.

To effectively enhance the spatial sensation for an immersive user experience (UX) in virtual reality (VR), the locomotion interface (LI) is one of the most critical factors. To offer a room-scale LI suitable for use in typical office or home environments, it is imperative that the LI device enables a natural walking experience while occupying minimal space. To realize LI for all directions, an omnidirectional treadmill (ODT) can successfully achieve 2-dimensional holonomic motion (X and Y axes) and provide the most natural walking experience, such as walking on real ground. However, a problem arises due to the excessive system thickness caused by the torus structure of a large treadmill (X-axis) carrying several small treadmills (Y-axis), along with the installation of a complex power transmission mechanism inside the ODT. To reduce the thickness of its double-layer and complex structure, we propose an ODT with a novel transmission mechanism. The proposed ODT utilizes helical timing pulleys (HTPs) to generate Y-axis motion and helical gears (HGs) to synchronized-actuate the HTPs. As a result, the proposed ODT achieves a super-thin configuration and fast actuation performance. A pilot test of the proposed ODT was conducted to assess its maximum performance. The results indicate achievable speeds of 3.175 m/s and 4 m/s, along with an acceleration of 5 m/s2 for both the X and Y axes, respectively.

In this paper, we present a spherical wheel-legged mobile robot, aiming to meet the demands of adaptability to complex terrains and high maneuverability. It consists of a spherical main body and five-bar linkage parallel wheel-legged mechanisms. It can switch between legged and spherical modes by extending and retracting its legs according to the demands of the actual environment, thereby enhancing the overall mobility of the robot. By designing the Linear Quadratic Regulator (LQR) controller, we achieve the impact-resistant leg balancing motion and autonomous pitch adjustment for the robot on inclined surfaces in the legged configuration. For the rolling control in the spherical configuration, a hierarchical sliding mode control method and Proportional-Integral-Derivative controller (PID) are employed to control the rolling and turning of the robot. We verify the robustness of the robot in wheel-legged configuration against disturbances and the stability of its motion in spherical configuration.

The limited workspace and complex singularity issues are predominant factors impeding the clinical applicability of fracture reduction parallel robots. To address these challenges, this paper proposes a novel redundant parallel mechanism (NRPM) for robotic-assisted fracture reduction with an enlarged workspace and enhanced dexterity capabilities based on the traditional Stewart parallel mechanism (SPM). With six redundant degrees-of-freedom (DOFs) added to the novel mechanism, the kinematics of NRPM needs to be thoroughly analyzed. Furthermore, the calculation of its workspace and determination of its dexterity are deduced. Both the analytical simulation and real experiment results demonstrated the effectiveness and superior performance of the proposed NRPM compared to SPM.

With the introduction of the Fourth Industrial Revolution and the spread of smart factories, the demand for small-quantity batch production systems is rapidly increasing. As a result, the implementation of robotic gripper systems that can handle various objects is required. Until now, grippers have to be replaced or newly developed each time depending on the object to be gripped. In addition, conventional gripper systems require a picking system based on a sophisticated gripping plan to handle products with complex shapes. This requires the integration of vision and various sensor systems, which in turn increases the cost of the system and makes it challenging to apply it to real industrial sites. To solve this problem, we developed a robotic finger by applying the paired crossed flexure hinge (p-CFH) developed in our previous research. The p-CFH-based robotic finger is driven by an underactuated wire-driven method that can be controlled by a single motor and has compliance and shape adaptive features. It also has the advantage of being modularized, easy to install and replace, and easy to maintain. The proposed finger module has a tip force of about 0.58 kg and its impact absorption capacity has been experimentally verified. In addition, gripping experiments were conducted on a total of four objects with different characteristics, and successful gripping was confirmed.

This paper presents the design and analysis of an omnidirectional reconfigurable wheeled robot capable of switching between omnidirectional and conventional wheeled mode. We have developed a new pneumatic locking mechanism of rollers for the mecanum wheel. In the mecanum mode, the robot can perform holonomic movements, and in the wheeled platform mode, it can overcome inclined surfaces and perform more energy-efficient movements. In addition, the locking device allows the robot to brake faster compared to other mecanum robots. Unlike other works describing the reconfigurable structure of the mecanum wheel, this work offers a new design characterized by the simplicity of the mechanism and does not require the location of active reconfiguration elements inside the wheel itself. The paper describes the design concept and presents the mechanism for locking rollers. The study evaluates the use of the developed robot in various scenarios, including movement on an inclined surface, sudden braking on a plane and an inclined surface, and also analyzes the energy efficiency of the resulting solution for some operating scenarios. The experiments carried out confirm that this mobile platform, when switching mode, is able to move on surfaces with a large angle of inclination and perform more effective deceleration on both flat and inclined surfaces.

This paper presents a novel pneumatic pouch sensor, designed to mount on a colonoscope, that can effectively estimate the contact forces with the environment. The pouch sensor was designed to maximize the sensing range, and it was fabricated using a 2D laser welding technique from our track record. A flow compensation (FC) algorithm was introduced to improve the accuracy of the sensor in the presence of static load. The proposed system can reliably measure external forces up to 9.5 N with high repeatability. The system allows discriminating between different levels of force which are typically associated with increasing patient discomfort in colonoscopy: low (0-4 N), medium (4-6 N), and high (>6 N). This system achieves over 80% accuracy in comparison to the ground truth under steady state conditions (P ≤ 0.05) and maintains over 68% accuracy in dynamic scenarios.

This paper introduces the Passive Transformable Omni-Ball (PTOB), an advanced omnidirectional wheel engineered to enhance step-climbing performance, incorporate built-in actuators, diminish vibrations, and fortify structural integrity. By modifying the omni-ball’s structure from two to three segments, we have achieved improved in-wheel actuation and a reduction in vibrational feedback. Additionally, we have implemented a sliding mechanism in the follower wheels to boost the wheel’s step-climbing abilities. A prototype with a 127 mm diameter PTOB was constructed, which confirmed its functionality for omnidirectional movement and internal actuation. Compared to a traditional omni-wheel, the PTOB demonstrated a comparable level of vibration while offering superior capabilities. Extensive testing in varied settings showed that the PTOB can adeptly handle step obstacles up to 45 mm, equivalent to 35 % of the wheel’s diameter, in both the forward and lateral directions. The PTOB showcased robust construction and proved to be versatile in navigating through environments with diverse obstacles.

Teleoperating bipedal humanoid robots presents unique challenges, including decreased stability and reduced operator presence. This paper addresses these challenges by proposing a method that leverages the operator’s inherent sense of stability by feedback from a sole haptics display to operate a bipedal humanoid robot. We developed a bilateral control system that integrates a device replicating sole haptics feedback and provides the operator with feedback on changes in the robot’s center of gravity. We conducted operating experiments in the forward-backward direction to evaluate its effectiveness and investigate the effectiveness of sole haptics on robot operation. The results demonstrate that operating with both vision and sole haptics feedback significantly reduces the robot’s fall rate by over 56% when disturbances are applied, compared to using only vision feedback. Moreover, operators reported a 21% higher sense of presence with both vision and sole haptics feedback compared to using only vision feedback.

A gripper mechanism using flexible double-rack finger actuated using differential worm gear mechanism that can change its finger length according to the object being grasped was developed. Thermoplastic polyurethane (TPU) based fingers were soft, impact resistant, highly compliant, and were able to conform to the contour of the objects when grasping. The fingers can extend, contract and bend in 2D space when driven by the differential worm gear mechanism. A normal worm and an inner worm gear was used to actuate the flexible double-rack fingers. The relative motions between the two worm gears resulted in different motions of the finger. Multiple fingered configuration of the gripper can be driven from the same mechanism actuated using two actuators. A mathematical model was developed to describe the kinematics of the finger for positioning experiments. Experiments were also conducted to measure the fingertip force for different lengths of the finger. Grasping experiments of two and three-finger gripper were performed to test the grasping performance of the gripper for objects of different size, shape and weight. The gripper successfully grasped objects of different sizes by adjusting the finger length and conforming to the shape of the objects.

Tactile sensors are crucial in robotics as they enable robots to perceive and interact with their environment through touch, akin to the human sense of touch. Adjustable sensors that can adapt to various tasks by functional or structural modification have not been extensively explored. In terms of sensing adjustability of a sensor, two important aspects are the sensor’s sensitivity and compliance. This paper proposes a novel design for an adjustable compliance and sensitivity sensor composed of a silicone base, a permanent magnet elastomer (PME), and a printed circuit board (PCB) with magnetic transducers installed. Its adjustability is achieved by varying the pneumatic pressure. This paper presents the design, manufacturing process, and experimental characterization of such an adjustable compliance and sensitivity sensor. This paper thoroughly investigates how altering the pressure of the sensor influences its sensing properties. The results show that it can achieve adjustability in all three axes. For the current design, the sensitivity can be varied from 0.093 to 0.125 mT/N (34.41%), 0.089 to 0.13 mT/N (31.54%), and 0.169 to 0.45 mT/N (62.44%) in the X-, Y-, and Z-axis, respectively. The deformation it undertakes varies from 3.20 to 3.79 mm (18.44%), indicating the compliance change.

This paper introduces the ‘Contextual Collision Risk (CCR)’ method, a novel collision risk assessment approach for autonomous navigation systems. As global shipping traffic increases, marine traffic becomes more complex and busier, requiring advanced risk assessment methods for autonomous vessels. The CCR establishes the Operational Envelope (OE) of autonomous navigation systems by integrating the complexities of real-time marine traffic and the specific maneuvering capabilities of own ship. The central aspect of CCR involves setting up Reachable Velocities (RV), which includes the dynamics of own ship. Additionally, the Velocity Obstacle (VO) algorithm is implemented to identify potential collision risks from other vessels. By integrating RV and VO analyses, CCR provides a framework that effectively quantifies collision risk in congested maritime environments. To demonstrate the effects of CCR, we employ data from transoceanic voyages across various scenarios. Furthermore, simulations of collision avoidance maneuvers are conducted, focusing on high-risk situations such as near-misses and potential collisions. In particular, the analysis of transoceanic voyage data shows that CCR holds promise for enhancing navigation safety in complex maritime environments.

Many studies have been conducted on Series Elastic Actuators (SEA) for robot joints because they are effective in terms of flexibility, safety, and energy efficiency. The ability of SEA to robustly handle unexpected disturbances has raised expectations for practical applications in environments where robots interact with humans. On the other hand, the development and commercialization of small robots for indoor entertainment applications is also actively underway, and it is thought that by using SEA in these robots, dynamic movements such as jumping and running can be realized. In this work, we developed a small and lightweight SEA using coil springs as elastic elements. By devising a method for fixing the coil spring, it is possible to absorb shock and perform highly accurate force measurement in both rotational directions with a simple structure. In addition, to verify the effectiveness of the developed SEA, we created a small single-legged robot with SEA implemented in the three joints of the hip, knee, and ankle, and we conducted a drop test. By adjusting the initial posture and control gain of each joint, we confirmed that flexible landing and continuous hopping are possible with simple PD position control. The measurement results showed that SEA is effective in terms of shock absorption and energy reuse.This work was performed for research purposes only.

The affordability and functionality of hand prosthetics in developing countries are still very limited. This work aims to present and evaluate the new version of the PrHand affordable robotic prosthesis (PrHand V3), built with soft robotics and compliant mechanisms. PrHand V3 implements a new frictionless tendon unification system, the degree of freedom of thumb opposition was removed, and the finger flexion was improved to the previous version, PrHand V2. The study contributes by evaluating these mechanical changes and conducting the first functional assessment of PrHand V3 with an amputee user. The Anthropomorphic Hand Assessment Protocol (AHAP) dexterity test was the first evaluation in this work; it evaluated how the prosthesis performs eight different grips. PrHand V3 was compared with a PrHand V2 and a commercial robotic prosthesis A3D from Prótesis Avanzadas SAS. PrHand V3’s score on the AHAP test was 80%. This result is higher than the 69% obtained by the PrHand V2 and the 79% obtained by A3D. The Activities Measure for Upper Limb Amputees (AM-ULA) test was the second evaluation in this work; An A3D amputee user performed 23 Activities of Daily Living with PrHand V3 and an A3D. PrHand V3 obtained an average of 2.86/4 and A3D obtained an average of 2.96/4 without significant differences between the two tests. The soft actuation of PrHand V3 as an affordable prosthesis performs similarly to a commercial robotic prosthesis with the advantage of being more flexible to assist a trans-radial hand amputee.

Visual inspection plays a predominant role in inspecting infrastructure surface. However, the generalization of existing visual inspection systems to large-scale real-world scenes remains challenging. In this paper, we introduce Det-Recon-Reg, an intelligent framework separating the complex inspection procedure into three stages: Detect, Reconstruct, and Register. (1) For defect detection (Detect), we present the first high-resolution defect dataset tailored for large-scale defect detection. Based on the dataset, we evaluate the most effective real-time object detection algorithms and push the boundary by proposing CUBIT-Net for real-world defect inspection. (2) For infrastructure reconstruction (Reconstruct), we propose a learning-based multi-view stereo (MVS) network to adapt to large-scale scenes, taking as input the multi-view images and outputting the point cloud reconstruction, where its performance has been validated on the standard MVS datasets, including BlendedMVS, DTU, and Tanks and Temples datasets. (3) For defect localization (Register), we propose an effective registration method based on the geographic information system that registers the detected defects onto the reconstructed infrastructure model to establish a global reference for maintenance measures. The real-world experiments further verify the effectiveness and efficiency of our proposed framework. More details about our proposed dataset, code, and appendix are available on our project page: https://cuhk-usr-group.github.io/large-scale-inspect-framework/.

This paper presents the design, prototype, and testing of a 150 g (current best estimate) manipulation system that enables Mars Sample Recovery Helicopter (SRH) concept to autonomously pickup, stow, and drop-off Returnable Sample Tube and Glove Assemblies (RGAs) on the surface of Mars next to the Sample Retrieval Lander (SRL). It consists of a 3 DOF planar Robotic Arm (RA), a novel 2 DOF Gripper with compliant fingers, and a Stow Mechanism. Within the planned Mars Sample Return (MSR) campaign, two SRHs would operate in parallel to retrieve and transfer total of 10 RGAs (146g each) to the SRL, as the backup to the Perseverance Rover. Once SRH arrives at the target pickup location, the RA places the Gripper precisely over the RGA. The gripper grabs and picks up RGAs using a linkage based non-back-drivable mechanism and its compliant fingers. Subsequently, the RA is secured into the stow features, following dislodging rocks and pebbles, by going through a specific sequence of joint trajectories. This ensures the RA and RGA are stable and secure during transit to the SRL while all Manipulation System actuators are powered off. The whole sequence of manipulation is performed autonomously using feedback of a pair of stereo-cameras and absolute encoders. Experimental evaluation of the Manipulation System performance has proved its robustness and consistency in successful RGA pickup, stow, and drop-off.

Soft continuum sections are widely used in robotic mechanisms for achieving dexterous motions. However, most available designs of soft continuum sections cannot support payload during a motion. This paper presents a development of a novel soft robotic wrist section for a prosthetic hand named ‘PRISMA Hand II’. Our research focuses on various phases of development of a soft continuum wrist section, that can support a substantial payload and maintain postures of the hand. Mechanical design, fabrication, and modelling strategies adopted for developing the wrist section are described. The design of the wrist section is constructed by assembling springs, discs, and tendons. The numbers and dimensions of springs and discs are optimised using static structural analysis. Kinematic modelling and dynamic modelling of the wrist section are carried out using Geometric Variable Strain (GVS) approach based on Cosserat rod theory and a generalised coordinate method respectively. The geometric formulations involved in Cosserat rod theory guaranteed accurate and quick computations considering deformation parameters. Dynamic modelling approach also enhanced the performance of the wrist section reducing errors and computational time during real time implementations. This paper also discusses about a dynamic model based controller strategy for the wrist section and advantages of the proposed controller are proved using a comparative study with a kinematic model based PID controller. Experimental validations of motions of the fabricated wrist section employing the dynamic controller are also included in the paper.