Development of a compact wrist with multiple working modes

Humanoid robotic manipulation in unstructured environments is a challenging problem. Limited perception, communications and environmental constraints present challenges that prevent fully autonomous or purely teleoperated robots from reliably interacting with their environment. In order to achieve higher reliability in manipulation we present an approach involving remote human supervision. Strengths from both human operator and humanoid robot are leveraged through a user interface that allows the operator to perceive the remote environment through an aggregated worldmodel based on onboard sensing, while the robot can efficiently receive perceptual and semantic information from the operator. A template based manipulation approach has been successfully applied to the Atlas humanoid robot; we show real world footage of the results obtained in the DARPA Robotics Challenge Trials 2013.

The study in this thesis addresses the problem of opening a door with a modular and reconfigurable robot (MRR) mounted on a wheeled mobile robot platform. The foremost issue with door opening problems is the prevention of occurrence of large internal forces that arise due to position errors or imprecise modeling of the robot or its environment, i.e. the door parameters, specifically. Unlike previous methods that relied on compliance control, making the control design rather complicated, this thesis presents a new concept that utilizes the multiple working modes of the MRR modules. The control design is significantly simplified by switching selected joints of the MRR to work in passive mode during door opening operation. As a result, the occurrence of large internal forces is prevented. Different control schemes are used for control of the joint modules in different working modes. For passive joint modules, a feedforward torque control approach is used to compensate the joint friction to ensure passive motion. For the active joint modules, a distributed control method, based on torque sensing, is used to facilitate the control of joint modules working under this mode. To enable autonomous door opening, an online door parameter estimation algorithm is proposed on the basis of the least squares method; and a path planning algorithm is developed on the basis of Hermite cubic spline functions, with consideration of motion constraints of the mobile MRR. The theory is validated using simulations and experimental results, as presented herein. A distributed fault detection scheme for MRR robots with joint torque sensing is also proposed in this thesis. The proposed scheme relies on filtering the joint torque command and comparing it with a filtered torque estimate that is derived from the nonlinear dynamic model of MRR with joint torque sensing. Common joint actuator faults are considered with fault detection being performed independently for each joint module. The proposed fault detection scheme for each module does not require motion states of any other module, making it an ideal modular approach for fault detection of modular robots. Experimental results have attested the effectiveness of the proposed fault detection scheme.

The progressive failure and scale effect of trap-door problems were evaluated, by comparing experimental results with finite element analyses employing the elasto-plastic model including the shear band effect. The experiments were performed in passive and active mode by measuring load-displacement relationships and observing shear band developments using two sizes of apparatus (the trap-door width of the smaller one was 5 cm and of the larger one 10 cm.) The load was measured with soil stress measurement cells embedded in the face of the trap-door. The shear band developments were observed using thin horizontal colored sand layers placed in the sand mass. The distribution of earth pressure by finite element analysis achieved good agreement with experimental results. The localized narrow zone of shear strain by the analysis was approximately identical with the observed shear band in both passive and active modes. The scale effect was recognized by the analysis and the experiment only in passive mode.

The localization of surgical tools and the patient’s reference coordinate system in three to six degrees of freedom is one of the key technologies in computer aided surgery. Several tracking methods are available, among which optical tracking is the most widespread in clinical use. Optical tracking technology has well proven to be a reliable method for intra-operative position and orientation acquisition for many clinical applications. However, the accuracy of these localizers is still a topic of discussion. In this paper, the accuracy of three optical localizer systems, the NDI Polaris P4, NDI Polaris Spectra (active and passive mode) and the Stryker Navigation System II Camera, is assessed and critically compared. Static tests revealed that only the Polaris P4 shows a significant warm up behavior with a significant shift of accuracy within 42 minutes after switching it on. Furthermore, the intrinsic localizer accuracy was determined for single markers as well as for typical tools using a volumetric measurement protocol on a coordinate measurement machine. To determine the relative distance error within the measurement volume, the Length Measurement Error (LME) was determined at 35 test lengths. The two active localizer systems, the Stryker Navigation System II camera and the Polaris Spectra (active mode), showed the best results with a trueness of 0.058±0.033mm and 0.089±0.061 mm, respectively (mean±std. dev.). The Polaris Spectra (passive mode) showed a trueness of 0.170±0.090mm and the Polaris P4 showed the lowest trueness with 0.272±0.394mm and a higher number of outliers than all the other cameras.

To study human motor control and learning in upper extremities, scientists widely use robotic arms to apply external forces to subject’s hand interactively. In this work, we describe the design procedure of a planar parallel manipulandum with five links and 2-DoF in a vertical plane (e.g. sagittal or frontal plane). The manipulandum works in two active and passive modes. In the passive mode, the robotic arm follows the movements of the human arm; while in the active mode, the robotic endeffector guides subject’s hand in any desired direction. In both active and passive conditions, the robot arm can be programmed to apply unexpected disturbances to the subjects hand. To control the movement of the manipulandum, we used two PID controllers with local shaft angle feedback to control the manipulandum. For the active mode, we used also a global feedback from endeffector position. As the first step for proof of concept, the whole system was simulated in MATLAB.

Mechanical ventilation is indispensable for patients with severe respiratory conditions, and high-fidelity lung simulators play a pivotal role in ventilator testing, clinical training, and respiratory research. However, most existing simulators are passive, single-lung models with limited and discrete control over respiratory mechanics, which constrains their ability to reproduce realistic breathing dynamics. To overcome these limitations, this study presents a dual-chamber lung simulator that can operate in both active and passive modes. The system integrates a sliding mode controller enhanced by a linear extended state observer, enabling the accurate replication of complex respiratory patterns. In active mode, the simulator allows for the precise tuning of respiratory muscle force profiles, lung compliance, and airway resistance to generate physiologically accurate flow and pressure waveforms. Notably, it can effectively simulate pathological conditions such as acute respiratory distress syndrome (ARDS) and chronic obstructive pulmonary disease (COPD) by adjusting key parameters to mimic the characteristic respiratory mechanics of these disorders. Experimental results show that the absolute flow error remains within ±3 L/min, and the response time is under 200 ms, ensuring rapid and reliable performance. In passive mode, the simulator emulates ventilator-dependent conditions, providing continuous adjustability of lung compliance from 30 to 100 mL/O and airway resistance from 2.01 to 14.67, with compliance deviations limited to ±5%. This design facilitates fine, continuous modulation of key respiratory parameters, making the system well-suited for evaluating ventilator performance, conducting human–machine interaction studies, and simulating pathological respiratory states.

Monitoring of microwave emission of HRP system during the enzyme functioning

Most conventional vital-sign sensing techniques are incompatible with the circuits in commercial wireless communication devices. In addition, conventional techniques cannot easily provide both active and passive sensing. This article presents a novel active/passive dual-mode sensing technique for detecting vital signs. The proposed technique simply combines the error vector magnitude (EVM) algorithm with the demodulation of wireless communication to detect vital signs. Therefore, any wireless device can be used as a vital-sign sensor without any modification of their circuits. The proposed technique can switch between active and passive modes as desired. The experimental results show that the developed sensing technique is very effective in detecting vital signs. In active mode, the maximum vital-sign detection distances of the developed 2.4-GHz sensor are 4.3 and 9 m with and without a 15-cm-thick reinforced concrete wall as a barrier, respectively. In passive mode, the developed sensor can penetrate a 15-cm-thick reinforced concrete wall to detect human vital signs within a range of 6.3 m.

A gripper is described for manipulation in natural, unstructured environments. The specific manipulation task is to pick up surface material such as pebbles or small rocks in a natural terrain. The application is to give autonomous sampling capabilities to an autonomous vehicle for planetary exploration. The authors describe the task analysis process that led to the selection of a configuration with three soft fingers. They carry out a complete analysis of the stability of a grasp for this gripper including an analysis of the deformation of the fingers at the points of contact. The implementation of a grasp selection algorithm is described, and results on three-dimensional representations of objects computed from range data are presented. >

Laboratory studies have been carried out to investigate the feasibility of removing air pollutant mixtures using sorbents, focusing on activated carbon and Purafi1. ‘Active mode’ tests (polluted air passing through the sorbent contained in a cartridge) with activated carbon, Purafil, molecular sieves and silica gel indicated that activated carbon was the most efficient sorbent for removal of the pollutants peroxyacetyl nitrate (PAN) in pure air, PAN and oxides of nitrogen in a smog mixture, and the chlorinated hydrocarbons 1,1, 1-trichloroethane (methyl chloroform), trichloroethylene and tetrachloroethylene. In the ‘passive mode’ (pollutant removal by diffusion to a bed ofsorbent in a display case) removal by sorbents and at the display case walls obeyed first order kinetics for all pollutants tested. The corresponding passive removal rate constants and pollutant half-lives have been determined. Carbon was more efficient than Purafil in all but one passive mode test. Several passive mode experimen...

Conventional suction cups lack sensing capabilities for contact-aware manipulation in unstructured environments. This paper presents FlexiCup, a multimodal suction cup with wireless electronics that integrate dual-zone vision-tactile sensing. The central zone dynamically switches between vision and tactile modalities via illumination control, while the peripheral zone provides continuous spatial awareness. The modular mechanical design supports both vacuum (sustained-contact adhesion) and Bernoulli (contactless lifting) actuation while maintaining the identical dual-zone sensing architecture, demonstrating sensing-actuation decoupling where sensing and actuation principles are orthogonally separable. We validate hardware versatility through dual control paradigms. Modular perception-driven grasping achieves comparable success rates across vacuum (90.0%) and Bernoulli (86.7%) modes using identical sensing and control pipelines, validating the sensing architecture's effectiveness across fundamentally different pneumatic principles. Diffusion-based end-to-end learning achieves 73.3% and 66.7% success on contact-aware manipulation tasks, with ablation studies confirming 13% improvements from multi-head attention coordinating dual-zone observations. Hardware designs, firmware, and experimental videos are available at the companion website: <uri xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">https://flexicup.junhaogong.top</uri>.

A portable solar still's productivity boost combining a magnetic stirrer and thermoelectric

The purpose of the study was to examine the effect of 1) active (loadless pedaling), 2) passive (assisted pedaling), and 3) inactive (motionless) recovery modes on mean arterial pressure (MAP), cutaneous vascular conductance (CVC), and sweat rate during recovery after 15 min of dynamic exercise in women. It was hypothesized that an active recovery mode would be most effective in attenuating the fall in MAP, CVC, and sweating during exercise recovery. Ten female subjects performed 15 min of cycle ergometer exercise at 70% of their predetermined peak oxygen consumption followed by 20 min of 1) active, 2) passive, or 3) inactive recovery. Mean skin temperature (Tsk), esophageal temperature (Tes), skin blood flow, sweating, cardiac output (CO), stroke volume (SV), heart rate (HR), total peripheral resistance (TPR), and MAP were recorded at baseline, end exercise, and 2, 5, 8, 12, 15, and 20 min postexercise. Cutaneous vascular conductance (CVC) was calculated as the ratio of laser-Doppler blood flow to MAP. In the active recovery mode, CVC, sweat rate, MAP, CO, and SV remained elevated over inactive values (P < 0.05). The passive mode was equally as effective as the active mode in maintaining MAP. Sweat rate was different among all modes after 12 min of recovery (P < 0.05). TPR during active recovery remained significantly lower than during recovery in the inactive mode (P < 0.05). No differences in either Tes or Tsk were observed among conditions. The results indicate that CVC can be modulated by central command and possibly cardiopulmonary baroreceptors in women. However, differences in sweat rate may be influenced by factors such as central command, mechanoreceptor stimulation, or cardiopulmonary baroreceptors.

A robot intended for assisting forearm rehabilitation of patients with neuromuscular disorders was designed. The robot can guide subject's forearm to pronate/supinate along planned seesaw-like or ramp-and-hold trajectories under a passive mode or an active mode. Preliminary tests on three normal subjects revealed that the robot could, in passive mode, guide the relaxed forearm of subjects to move in the planned trajectory and, in active mode, apply a specified torque on the forearm during voluntary movement.

In recent development of vehicular adhoc network the consumption of energy by its nodes is major problem now a day. To overcome this problem many algorithms are proposed effectively by different researcher. The two main aspects that can resolve this issue is by having proper routing and network design. Many existing routing protocols are available with vehicular adhoc network, but only few of them can be utilize to resolve with the energy efficient problem. In wireless sensor network when the nodes are deployed they consumed most of the energy continuously to broadcast the message in multi hop connectivity. Generally nodes remain active even when there is no message to forward. This keeps decreasing the energy level of sink node. As a result the performance of the network gets dropped down. In our proposed algorithm, we aim to resolve this by relaying the node energy between active and passive mode. In our methodology sensor nodes gets triggered into active mode after a specific interval of time to exchange its data among them. The simulation results show that our proposed scheme, surpass from the other existing schemes. At the same time, each sensor node will restore its energy at regular interval as well as maintain high reception rate and low delay for multi-hop network.