Teleoperated robotic surgical systems such as daVinci are widely used for laparoscopic surgeries. The currently available daVinci system does not provide haptic feedback. Prior research has shown that the addition of haptic feedback improves surgeons' performance during minimally invasive surgeries. Other authors have implemented haptic feedback in the daVinci robot, but some issues made them impractical for clinical use. In this work, two strain gauge force-sensing devices were created for the patient side manipulator of the daVinci surgical robot. These devices were designed to be easily added to the existing system and used for the real-time force feedback in the daVinci robot. The proposed system has high sensitivity and resolution, matches the required force measurement range, and has high signal-to-noise ratio, which implies high signal quality. However, the absolute errors of the currently built devices are high due to the manufacturing techniques used on the prototype that could be improved upon for a deployed device. This work demonstrates fast 3-DOF force measurements on the daVinci robot without any robot or instrument modifications. While the present system has significant systematic errors, these can be mitigated by altering the mechanical design to improve the accuracy of the system.

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Laparoscopic surgery provides major benefits to patients in terms of decreased pain and post-operative hospital stays, but also increases their risks of intra-operative injuries because of the reduction in feedback in the tactile and visual channels compared to open surgery. Although the limitations of laparoscopy have been studied, the specific role of force feedback in laparoscopic surgery performance is not well understood. The purpose of this thesis is to determine the effect of force feedback on the ability to accurately discriminate tissue compliance by comparing subjective tissue softness assessment, force output, and subjective force assessment, in conventional and laparoscopic setups. The experimental trials involved eleven participants providing evaluations for a range of compliant samples, and analyzed their force output as well as their subjective evaluation of force output. The results of this investigation show that the accuracy of compliance discrimination is worse when using indirect probing compared to direct probing, and that the force used in direct probing is lower than the indirect scenario. Further, the subjective assessment of force output in direct probing is not significantly different compared to indirect probing. Further research involving more replication, expert of laparoscopy, and a focus on grip force are recommended to better understand our awareness of the subjective force output.

Laparoscopic surgery provides major benefits to patients in terms of decreased pain and post-operative hospital stays, but also increases their risks of intra-operative injuries because of the reduction in feedback in the tactile and visual channels compared to open surgery. Although the limitations of laparoscopy have been studied, the specific role of force feedback in laparoscopic surgery performance is not well understood. The purpose of this thesis is to determine the effect of force feedback on the ability to accurately discriminate tissue compliance by comparing subjective tissue softness assessment, force output, and subjective force assessment, in conventional and laparoscopic setups. The experimental trials involved eleven participants providing evaluations for a range of compliant samples, and analyzed their force output as well as their subjective evaluation of force output. The results of this investigation show that the accuracy of compliance discrimination is worse when using indirect probing compared to direct probing, and that the force used in direct probing is lower than the indirect scenario. Further, the subjective assessment of force output in direct probing is not significantly different compared to indirect probing. Further research involving more replication, expert of laparoscopy, and a focus on grip force are recommended to better understand our awareness of the subjective force output.

The subject of diploma project is constructional solution of haptics interface construction for virtual reality output device. Construction is oriented only for virtual contact with objects. Force feedback on the user and deformation of objects are not used. Used programs: Autodesk INVENTOR 10, ANSYS WORKBENCH.

Semi-active suspension systems promise to significantly reduce the necessary trade-off be-tween handling and passenger comfort present in conventional suspension systems by enabling active chassis and wheel control. Öhlins Racing AB have developed a semi-active suspension technology known as CES, Continuously controlled Electronic Suspension, based on solenoid control valves which are integrated into specially designed hydraulic dampers, and are currently developing control and estimation systems which will enable their application in advanced motorcycle suspensions. In these systems an important aspect is being able to accurately control the forces produced. Öhlins’ current system uses an open loop control strategy in which currents sent through the solenoid valves, to achieve the requested damping force under the prevailing circumstances, is calculated using experimentally derived static lookup tables. In this thesis a new closed loop control system, based on the direct measurement of the damper force, is developed and its performance is evaluated in comparison to the old one’s. Sufficient understanding of the system requires extensive modeling and therefore two different models have been developed; a simpler one used for model based control design and a more extensive, high fidelity model used for high accuracy simulations. The developed simulation model is the first of its kind that is able to capture the studied systems behavior with satisfactory accuracy, as demonstrated against real dynamometer measurements. The valves and damper behave in a highly non linear manner and the final controller design uses a combination of exact linearization, non linear state estimation, dynamical inversion and classical control theory. Simulation results indicate that the new controller reduces the root mean square force tracking error to about 63% of that of the existing controller in the evaluation scenarios used. Cascaded within the system is also closed loop current controllers. A developed model based controller is shown to reduce the rise time to less than 30% of that of the existing PID-controllers, reduce the overshoot and provide online estimates of the winding series resistance, providing the basis for future solenoid diagnosis and temperature tracking systems.

<p>Industrial robots have been used for a long time in the industry. Despite this thedevelopment of advanced force control system using industrial robots is relativelylimited. Using force controlled robot systems expands the possibility of what canbe done with industrial robots.Previously a force feedback system for a standard industrial robot from ABBhas been developed. The system is developed towards the aircraft industry, where amounted drill machine on the robot has to fulfill the requirements in robot drillingin aircraft structures. This thesis presents experimental results and improvementsof this industrial robot system. Mechanical modifications and tests of a new endeffector are analyzed.</p>

This thesis work is about further developing an existing capacitive MEMS sensor for in situ TEM nanoindentation developed by Nanofactory Instrument AB. Today, this sensor uses a parallel plate capacitor suspended by springs to measure the applied force. The forces are in the micro Newton range. One major issue using with this measurement technique is that the tip mounted on one of the sensor plates can move out of the TEM image when a force is applied. In order to improve the measurement technique electrostatic feedback has been investigated. The sensor’s electrostatic properties have been evaluated using Capacitance-Voltage measurements and a white light interferometer has been used to directly measure the displacement of the sensor with varying voltage. Investigation of the sensor is described with analytical models with detailed treatment of the capacitive response as function of electrostatic actuation. The model has been tested and refined by using experimental data. The model showed the existence of a serial capacitor in the sensor. Moreover, a feedback loop was tested, by using small beads as load and by manually adjusting the voltage. With the success of controlling the feedback loop manually, it is shown that the idea is feasible, but some modifications and improvements are needed to perform it more smoothly.

As the progress of computer, virtual reality has become a more and more widespread technology and is applied extensively in entertainment, training, or medical science. To increase the interaction and reality of the virtual technology, the development of haptic feedback improves rapidly in recent years. This paper focuses on judgment existing collision detection algorithms, virtual wall models, and friction models from the view point of man-machine interface. A virtual environment interface with force feedback by using a joystick for computer game as a haptic device is established. A virtual environment is also built by employing the DirectX, a 3D computer graphic software developed by Microsoft Corp. Three virtual wall models are compared and four operational experiments are conducted to explore the influence of force feedback on operation task in virtual environment.

<p>This thesis work is about further developing an existing capacitive MEMS sensor for in situ TEM nanoindentation developed by Nanofactory Instrument AB. Today, this sensor uses a parallel plate capacitor suspended by springs to measure the applied force. The forces are in the micro Newton range. One major issue using with this measurement technique is that the tip mounted on one of the sensor plates can move out of the TEM image when a force is applied. In order to improve the measurement technique electrostatic feedback has been investigated. The sensor’s electrostatic properties have been evaluated using Capacitance-Voltage measurements and a white light interferometer has been used to directly measure the displacement of the sensor with varying voltage. Investigation of the sensor is described with analytical models with detailed treatment of the capacitive response as function of electrostatic actuation. The model has been tested and refined by using experimental data. The model showed the existence of a serial capacitor in the sensor. Moreover, a feedback loop was tested, by using small beads as load and by manually adjusting the voltage. With the success of controlling the feedback loop manually, it is shown that the idea is feasible, but some modifications and improvements are needed to perform it more smoothly.</p>