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The purpose of this paper is to present a surgical robot for spinal fusion and its control framework that provides higher operation accuracy, greater flexibility of robot position control, and improved ergonomics.

A human‐guided robot for the spinal fusion surgery has been developed with a dexterous end‐effector that is capable of high‐speed drilling for cortical layer gimleting and tele‐operated insertion of screws into the vertebrae. The end‐effector is position‐controlled by a five degrees‐of‐freedom robot body that has a kinematically closed structure to withstand strong reaction force occurring in the surgery. The robot also allows the surgeon to control cooperatively the position and orientation of the end‐effector in order to provide maximum flexibility in exploiting his or her expertise. Also incorporated for improved safety is a “drill‐by‐wire” mechanism wherein a screw is tele‐drilled by the surgeon in a mechanically decoupled master/slave system. Finally, a torque‐rendering algorithm that adds synthetic open‐loop high‐frequency components on feedback torque increases the realism of tele‐drilling in the screw‐by‐wire mechanism.

Experimental results indicated that this assistive robot for spinal fusion performs drilling tasks within the static regulation errors less than 0.1 μm for position control and less than 0.05° for orientation control. The users of the tele‐drilling reported subjectively that they experienced torque feedback similar to that of direct screw insertion.

Although the robotic surgery system itself has been developed, integration with surgery planning and tracking systems is ongoing. Thus, the screw insertion accuracy of a whole surgery system with the assistive robot is to be investigated in the near future.

The paper arguably pioneers the dexterous end‐effector appropriately designed for spinal fusion, the cooperative robot position‐control algorithm, the screw‐by‐wire mechanism for indirect screw insertion, and the torque‐rendering algorithm for more realistic torque feedback. In particular, the system has the potential of circumventing the screw‐loosening problem, a common defect in the conventional surgeon‐operated or robot‐assisted spinal fusion surgery.

This paper aims to propose an improved direct torque control (DTC) for the induction motor’s performance enhancement using dual nonlinear techniques. The exact feedback linearization is implemented to create a linear decoupled control. Besides, the fuzzy logic control approach has been inserted to generate the auxiliary control input for the feedback linearization controller.

To improve the DTC for induction motor drive, this work suggests the incorporation of two nonlinear approaches. As the classical feedback linearization suffers while the presence of uncertainties and modeling inaccuracy, it is recommended to be associated to another robust control approach to compensate the uncertainties of the model and make a robust control versus the variations of the machine parameters. Therefore, fuzzy logic controllers will be integrated as auxiliary inputs to the feedback linearization control law.

The simulation and the experimental validation of the proposed control algorithm show that the association of dual techniques can effectively achieve high dynamic behavior and improve the robustness against parameters variation and external disturbances. Moreover, the space vector modulation is used to preserve a fixed switching frequency, reduce ripples and low switching losses.

The theoretical, simulation and experimental studies prove that the proposed control algorithm can be used on different AC machines for variable speed drive applications such as oil drilling, traction systems and wind energy conversion systems.

The proposed DTC strategy has been developed theoretically and realized through simulation and experimental implementation. Different operation conditions have been conducted to check the ability and robustness of the control strategy, such as steady state, speed reversal maneuver, low-speed operation and parameters variation test with load application.

Legged robots are inevitably to interact with the environment while they are moving. This paper aims to properly handle these interactions. It works to actively control the joint torques of a hydraulic-actuated leg prototype and achieve compliant motion of the leg.

This work focuses on the modelling and controlling of a hydraulic-actuated robot leg prototype. First, the design and kinematics of the leg prototype is introduced. Then the linearlized model for the hydraulic actuator is built, and a model-based leg joint torque controller is presented. Furthermore, the virtual model controller is implemented on the prototype leg to achieve active compliance of the leg. Effectiveness of the controllers are validated through the experiments on the physical platform as well as the results from simulations.

The hydraulic joint torque controller presented in this paper shows good torque tracking performance. And the actively compliant leg successfully emulates the performance of virtual passive components under dynamic situations.

The main contribution of this paper is that it proposed a model-based active compliance controller for the hydraulic-actuated robot leg. It will be helpful for those robots that aim to achieve versatile and safe motions.

Hot‐cells are shielded structures protecting individuals from radioactive materials. The purpose of this paper is to propose a design approach for a hot‐cell simulator using digital mock‐up (DMU) technology and combining Haptic guided complex robotic manipulation for assembly tasks in a virtual environment.

The principal reason for developing a simulator was to explore the feasibility of hot‐cell structure design and collision‐free assembly process. For this, a simulation design philosophy has been proposed that includes DMU facility offering the ability of analyzing the operations and performing complex robotic manipulations in the virtual hot‐cell environment. Furthermore, enhanced Haptic mapping for tele‐manipulation is proposed for training and guidance purposes.

From the analysis and task scenarios performed in virtual simulator, the optimal positions of the manipulators and need of (bridge transport dual arm servo‐manipulators) type were identified. Operation tasks were performed remotely using virtual hot‐cell technology by simulating the scenarios in the DMU reducing the overall operation cost and user training. The graphic simulator substantially reduced the cost of the process and maintenance procedure as well as the process equipment by providing a pre‐analysis of whole scenario for real manipulation.

This research tries to contribute to the virtual hot‐cell design philosophy. Tele‐operated complex robotic operations in DMU technology are performed in virtual hot‐cell. The simulator provides improved Haptic guidance with force and torque feedback enhancing the realism of virtual environment.

The objective of this work was to demonstrate a novel approach to human machine interaction that seamlessly uses teleoperation and automation in a complex environment.

This work leverages developments in the area of operational software Operational Software Components for Advanced Robotics (OSCAR), decision making, human‐machine interface, and motion planning. This demonstration uses a 17 degrees‐of‐freedom (DOF) dual arm robot that is equipped with modern tool changers, crash protectors, force‐torque sensors and electrical and pneumatic power at the tools. Four different end‐effector tools are also provided. These are electric grippers, electric rotary saw, electric drill, and a pneumatic spray gun. The system can be used both in teleoperation and automation mode. In teleoperation mode, the user has a choice of five different input devices. These are computer keyboard, spaceball and spacemouse, RSI manual controller and kraft force feedback controller. Automation is performed using a novel graphical user interface with 3D graphics used for previewing and verifying manipulator motion. Automation tasks that are demonstrated include automatic grasping, sawing, drilling, spray painting, point‐to‐point motion, and teaching. The controller for the dual arm system is developed using OSCAR and supports a variety of decision‐making algorithms and obstacle avoidance. The integration of this controller with the input devices and human machine interface is done using a novel protocol that is based on Extensible Markup Language (XML) for maximum reuse and distributed integration. This protocol is further based on a well‐defined and scalable XML schema that can be easily extended as controller functionality is changed and/or additional input devices are added.

It is necessary to combine automation with teleoperation to reduce worker fatigue and also provide higher value robotic functions. This is possible as most remote tasks can be broken down into structured and unstructured components. On the integration front, we see XML‐based integration providing a loosely coupled system that can make interoperability between various robot systems possible. For end‐effector tooling, it is better to have special purpose tools that can be switched out versus the use of a general purpose tool such as a robotic hand.

This research was done in a laboratory environment, and as such, its application in the field will require partnering with a commercial entity. Force‐feedback on manual controllers during teleoperation was not very effective. In fact, providing visual queues to the operator about the forces were a better guide to the operator.

The software for this work provides obstacle avoidance capability. The obstacle avoidance is based on a known world model that is derived from a CAD environment. In reality, this model will have to be sensed in real‐time, and decoded into a geometric model. Significant work in this area needs to be done.

The software developed for this work was based on the OSCAR software framework. This is a unique framework that at its core uses performance criteria to control the behavior of the robot during teleoperation and automation. The value of this work is that it shows as completely feasible the control of a 17 DOF dual arm system using the latest integration technologies (such as XML), integrated simulation, multiple tools and multiple input devices. It also shows that all these choices can be provided to an operator through a single user interface.

The present paper will discuss newly developed fully digital sensorless induction motor and permanent magnet motor synchronous motor drives, which employ natural field orientation (NFO). So far only vector‐type of NFO induction motor drives have been discussed in the literature, and very limited experimental results have been shown. In addition, the paper will also discuss new sensorless DTC‐type of NFO induction motor drives (NFO‐DTC drives). Using fully digital implementations of the new NFO‐type induction motor and permanent magnet drives, experimental results will be shown for various operating conditions, including slow and fast reversals at very low speed. Robustness to parameter deviations will also be demonstrated. The developed new types of NFO drives can also work at zero stator frequency and sustained zero frequency operation will also be demonstrated. The drives have been tested in basically two environments: where the load is a dc motor; and where a crane drive is implemented. In contrast to other sensorless crane drives, which develop stability problems, it was found that the new NFO drives can operate in a stable manner under all operating conditions including zero frequency. This allows for many new applications.

The purpose of this paper is to discuss the design and verification of a non‐classical structure of servo‐drive controller with the state feedback and a load torque feedforward compensation.

First a well known nonlinear mathematical model of a PMSM is transformed into a linear form by introducing new variables. The state space new model presented in rotated orthogonal reference frame is decoupled by means of equation in d and q axis. To achieve correct dynamic performance of the servo‐drive system the state feedback with an internal input model and load torque feedforward compensation is proposed. The observed load torque has been used as an input signal for the feedforward compensator. The design of the control system and simulation analysis were performed in Matlab/Simulink. The proposed control algorithm was implemented in a DSP controller (TMS320F2812). The experiments were carried out by using a 0.6 kW PMSM drive system.

It is shown that the proposed compensator can eliminate the effects of load torque changes by steady‐state operation and significantly improve dynamic behaviour during load changing. A novel mathematical formula how calculate an appropriate gain for feedforward compensator is given.

Analysis of possible disturbance compensation shows that full dynamic compensation of disturbance is impossible. Only the compensation of load torque for a steady state is possible. The described control structure operates without state variables limitations so it is not recommended to application where the high dynamic of transient process is required.

The proposed control system can be used in industrial applications where load torque compensation is needed instead the high dynamic performance.

Presented mathematical formula how calculate an appropriate gain for feedforward compensator is a theoretical contribution of the authors. The test results are consistent with the computer simulation test results and validate the correct dynamic performance of the proposed control method.

The purpose of this study is to propose a torque vectoring control system for improving the handling stability of distributed drive electric buses under complicated driving conditions. Energy crisis and environment pollution are two key pressing issues faced by mankind. Pure electric buses are recognized as the effective method to solve the problems. Distributed drive electric buses (DDEBs) as an emerging mode of pure electric buses are attracting intense research interests around the world. Compared with the central driven electric buses, DDEB is able to control the driving and braking torque of each wheel individually and accurately to significantly enhance the handling stability. Therefore, the torque vectoring control (TVC) system is proposed to allocate the driving torque among four wheels reasonably to improve the handling stability of DDEBs.

The proposed TVC system is designed based on hierarchical control. The upper layer is direct yaw moment controller based on feedforward and feedback control. The feedforward control algorithm is designed to calculate the desired steady-state yaw moment based on the steering wheel angle and the longitudinal velocity. The feedback control is anti-windup sliding mode control algorithm, which takes the errors between actual and reference yaw rate as the control variables. The lower layer is torque allocation controller, including economical torque allocation control algorithm and optimal torque allocation control algorithm.

The steady static circular test has been carried out to demonstrate the effectiveness and control effort of the proposed TVC system. Compared with the field experiment results of tested bus with TVC system and without TVC system, the slip angle of tested bus with TVC system is much less than without TVC. And the actual yaw rate of tested bus with TVC system is able to track the reference yaw rate completely. The experiment results demonstrate that the TVC system has a remarkable performance in the real practice and improve the handling stability effectively.

In view of the large load transfer, the strong coupling characteristics of tire , the suspension and the steering system during coach corning, the vehicle reference steering characteristics is defined considering vehicle nonlinear characteristics and the feedforward term of torque vectoring control at different steering angles and speeds is designed. Meanwhile, in order to improve the robustness of controller, an anti-integral saturation sliding mode variable structure control algorithm is proposed as the feedback term of torque vectoring control.

The purpose of this paper is to enhance the performance of robots in peg-in-hole assembly tasks, enabling them to swiftly and robustly accomplish the task. It also focuses on the robot’s ability to generalize across assemblies with different hole sizes.

Human behavior in peg-in-hole assembly serves as inspiration, where individuals visually locate the hole firstly and then continuously adjust the peg pose based on force/torque feedback during the insertion process. This paper proposes a novel framework that integrate visual servo and adjustment based on force/torque feedback, the authors use deep neural network (DNN) and image processing techniques to determine the pose of hole, then an incremental learning approach based on a broad learning system (BLS) is used to simulate human learning ability, the number of adjustments required for insertion process is continuously reduced.

The author conducted experiments on visual servo, adjustment based on force/torque feedback, and the proposed framework. Visual servo inferred the pixel position and orientation of the target hole in only about 0.12 s, and the robot achieved peg insertion with 1–3 adjustments based on force/torque feedback. The success rate for peg-in-hole assembly using the proposed framework was 100%. These results proved the effectiveness of the proposed framework.

This paper proposes a framework for peg-in-hole assembly that combines visual servo and adjustment based on force/torque feedback. The assembly tasks are accomplished using DNN, image processing and BLS. To the best of the authors’ knowledge, no similar methods were found in other people’s work. Therefore, the authors believe that this work is original.

The purpose of this paper is to present a simple yet effective force control scheme for collaborative robots by addressing the problem of disturbance rejection in joint torque: inherent actuator flexibility and nonlinear friction.

In this paper, a joint torque controller with an extended state observer is used to decouple the joint actuators from the multi-rigid-body system of a constrained robot and compensate the motor friction. Moreover, to realize robot force control, the authors embed this controller into the impedance control framework.

Results have been given in simulations and experiments in which the proposed joint torque controller with an extended state observer can effectively estimate and compensate the total disturbance. The overall control framework is analytically proved to be stable, and further it is validated in experiments with a robot testbed.

With the proposed robot force controller, the robot is able to change its stiffness in real time and therefore take variable tasks without any accessories, such as the RCC or 6-DOF F/T sensor. In addition, programing by demonstration can be realized easily within the proposed framework, which makes the robot accessible to unprofessional users.

The main contribution of the presented work is the design of a model-free robot force controller with the ability to reject torque disturbances from robot-actuator coupling effect and motor friction, applicable for both constrained and unconstrained environments. Simulation and experiment results from a 7-DOF robot are given to show the effectiveness and robustness of the proposed controller.