Human-Robot Co-Working is an active research domain in the field of robotics and control theory. Most of pioneering contributions addressing Co-Working interaction control problems has focused on PID based control. On the other hand, there are, in modern control theory, several tools allowing to design and tune arbitrarily complex servo-controllers. Non-Smooth optimization is one of recently developed tools that addresses the problem of tuning structured controllers according to H∞, H2, and pole placement specifications. In this paper, the problem of force amplification is transcribed into high level H∞specifications and is solved using Non-Smooth optimization. The resulting controller is tested on an industrial robot and shows similar performances as the state of the art while respecting some extra robustness certificates. Therefore, thanks to the abstraction level of the proposed technique, it becomes possible to tune interaction controllers with high number of tunable parameters according to complex performance/robustness specifications.

Accurately localize a mobile vehicle with an easy and quickly deployable system can be very useful for many applications. Herein we present an EKF-SLAM algorithm which allows using radio frequency (RF) beacons without any prior knowledge of their location. As RF beacons provide only range information, recovering their positions is not an easy task. For this range-only SLAM case, a new procedure to instantiate the beacons in the filter is proposed. The method uses two range measurements from different robot's positions to initialize two hypotheses for the beacon's location, which are then integrated in the filter as a Gaussian mixture. This approach is evaluated and compared to other initialization techniques in simulation and with a real dataset. The results show that our approach performs as well as the other existing methods for both trajectory and map errors with a low computational cost.

We present herein an original solution to actively stabilize the epicardium in the context of beating-heart coronary artery bypass grafting. Our solution uses a control moment gyroscope to generate the compensation torque and an accelerometer for sensing. This approach makes the designed system completely independent from the stabilizing instrument, as well as independent from any external measurement. We compare two control approaches in a simulation: The first one uses a Kalman filter with a harmonic disturbance model, and the second one uses an adaptive algorithm. Results highlight the superiority of the adaptive control for our application. The first in vivo assessments are presented, showing the efficiency of the principle under real conditions. Using only accelerometric measurements, targeted cardiac motion harmonics are reduced on the order of 68%. With an optical sensor, the reduction exceeds 90%. This constitutes an improvement compared with prior solutions, despite the presence of nonnegligible uncertainties and distant sensing.

Active heart stabilization can help the development of less invasive surgical techniques in the cardiac field. The GyroLock device we propose insures this function using Control Moment Gyro (CMG) actuation, which avoids linkage to the environment. This system is completely independent and pluggable on commercial instruments. For control we use an adaptive algorithm featuring harmonic disturbance cancellation. The first in vivo experiments of the GyroLock using the adaptive control are presented and the results based on two sensor technologies are compared. They exhibit a displacement reduction of more than 90% for cardiac harmonics.

When using a camera as a position sensor, the measurement is limited in bandwidth, mainly due to the blur effects. The knowledge of an accurate model of the camera is then necessary to reconstruct the trajectory from the measurements given by the camera. This paper deals with the reconstruction of the continuous-time trajectory from the discrete-time measurements provided by the camera and shows the improvement obtained by using an accurate camera model. In the proposed methodology, a Kalman filter is used for the data fusion between the model and the measurement. The tuning and implementation of the filter are discussed in the specific context of the camera measurement. The system is evaluated in the context of a biomedical application: the reconstruction of the movement of a beating-heart.

In this paper, control strategies for an active stabilizer dedicated to beating heart coronary artery bypass grafting are investigated. The active stabilizer, which consists of a piezoactuated compliant mechanism, has to be controlled to compensate for the displacements induced by the beating heart in order to provide the surgeon with a locally motionless myocardium surface. Three controllers, including different levels of prior knowledge about the heart motion, are presented. Their performance with respect to modeling uncertainties, arising unknown interactions of the stabilizer with its positioning mechanism, and the heart, is studied through simulations, as well as laboratory and in vivo experiments. Finally, the selection of the most adequate control scheme and the performance of the device from a clinical point of view are discussed.

In this paper, the design of a new active cardiac stabilizer, Cardiolock2, is presented. Following the proof of concept Cardiolock [7], this device allows an active stabilization of the surface of a beating heart in two directions, which is considered sufficient for a complete stabilization. Piezoelectric actuation is combined with a compliant architecture to obtain high dynamics and accuracy. A remote center of motion is obtained with a serial architecture, and parallel mechanisms in configurations close to singularity are used to increase the workspace. A kinematic analysis is first presented, before detailing the main properties of the device and the current development of the prototype.

Vision can be used as a sensor for measuring the position of a visual marker. When the displacement of the marker over the camera exposure time is significant, the obtained position measurement is an image of the trajectory over the exposure time. This paper deals with dynamical models providing a prediction of the measurement from the continuous-time trajectory. The first contribution of the paper consists in the development of models for the global shutter and rolling shutter modes with variable exposure time. The second contribution consists in a methodology for the validation of these models. This methodology is used for validating the model of a camera with global shutter mode with full exposure time.

This paper addresses the influence of human operators on telemanipulators bilateral control. A method to deal with the user variability is proposed, based on the auto-tuning of the force controller at the master side. First, the approach is evaluated experimentally with a group of users in the context of nonlinear interactions with soft tissues, showing very good tracking performances, for both force and position. Second, a robustness analysis is presented that allows to prove the stability of the system for large variations of the behavior of both the environment and the user. This analysis is based on an original uncertain model of the user.

Off-pump coronary artery bypass grafting (CABG) is probably an important milestone in the cardiac surgery history. This technique is currently made possible thanks to the use of mechanical stabilizers. Nevertheless, the available stabilizers are not fully satisfying. Indeed, they have been demonstrated to exhibit significant residual motion. In this paper we propose a novel piezo-actuated compliant stabilizer, whose architecture is compatible with a minimally invasive surgery context. This active stabilizer is controlled using high speed visual feedback in order to compensate in real time for the residual cardiac motion. In vivo experimental results using the developed prototype are given to demonstrate the efficiency of the adopted approach.

In this paper is considered fast visual servoing of a two-links arm including flexibilities for compensation of heart movements in surgery. The flexibilities are globally identified with no additional sensor than the external-500 Hz camera used in the visual servoing loop. The obtained model is valid around the working position of the arm and can be easily modified for new positions of the camera. Two control strategies to handle flexibilities and achieve high bandwidth are implemented: Generalized Predictive Control (GPC) and H∞ control. Simulation and experimental results are given allowing to compare their efficiencies.