パラレルワイヤ型クレーンのコンプライアンス制御

A practical compliance control method has been developed for a robot manipulator. The developed method has the following features from its practical point of view. 1) The responsibility of position control is not reduced, although the compliance is set high, where a manipulator hand is not constrained from its environment. 2) Easy and continuous change between compliance, force and position control is possible. 3) The reference signals to joints of a manipulator are rate signal. In this paper, the compliance control law which satisfies these features simultaneously was applied to a one-degree-of-freedom model of a manipulator is consideration of the stiffness of its driving wires and gears. As a result, the propriety of the control law has been confirmed through analyses and experiments.

This article raises the problem of improving the analysis of the financial condition of an eco-nomic entity and its use in the compliance control system. The main tasks of using the analysis in the compliance control system in order to increase the efficiency of corporate management of the economic activity of an economic entity have been determined. It is emphasized that the analysis of the financial condition is one of the mandatory components of both internal control and compliance control, the differences in the use of the analysis results are analyzed. It is concluded that the role of financial analysis and its use in the compliance control system in order to improve the efficiency of corporate governance is constantly increasing in order to prevent compliance risks and regulatory risks due to external influence of supervisors.

Application of μ theory in compliant force control system is studied. Compliant force control strategy is developed based on the inner loop position control of 6-DOF parallel robot in order to simulate pushing and pulling procedure of forcible alignment of space docking. The cascade structure of "out-force-loop containing inner-position-loop" is depicted, and the method is set forth using classical control strategy to realize compliant force control. Considering uncertainties such as parameter perturbations, model perturbations and external disturbances, etc, robust force controller is designed using μ synthesis theory. It is listed in detail that the selection method of weighting functions in robust compliant force control loop and the designing procedure of robust force controller. Robust stability and robust performance are compared between robust force controller and classical force controllers by μ analysis. Experiment of robust force controller and classical force controllers is presented. The results indicate that the designed robust force controller is of efficiency and superiority.

In modern conditions, compliance is the basis for improving the management decision-making process, contributes to the achievement of the established strategic and tactical goals of the enterprise and ensures its sustainable development in the long term. In this connection, the functions of compliance control are significantly expanded. The subject of the article’s research is the compliance control system, which is a complex of types of controls built into the business processes of economic entities, established to comply with certain standards. The purpose of the work is to improve the theoretical and practical aspects of the formation of the compliance control system at enterprises. To achieve the goal, the following tasks should be solved: to systematize the theoretical and methodological approaches to the concept of "compliance control", to generalize the areas of regulation of companies’ activities with the help of compliance control, to specify the types of compliance risks. Consider the peculiarities of compliance control, its components and the structure of the compliance program. To achieve the goal of the work, a set of general scientific methods was applied: abstract-logical generalization; comparative comparison of playing; analysis and synthesis. As a result of the conducted research, directions, types and features of compliance control and compliance risks, features of the composition of the compliance program were specified. Conclusions: the implementation of compliance control provides enterprises with indisputable advantages in the form of image improvement; simplification of algorithms for interaction with supervisory and regulatory bodies; increasing the level of corporate culture – continuous monitoring of risk situations and smooth introduction of compliance procedures into the company’s work contributes to the improvement of business processes and the formation of a dynamic environment for the creation of an innovative climate and the emergence of a "corporate spirit", which involves clear compliance with ethical standards in relation to counterparties; the possibility of establishing new partnerships; the possibility of presence on international markets – the implementation of compliance in transnational companies and companies that plan to enter the international level increases their trust on the part of foreign stakeholders.

Simultaneous force and Position control is indispensable for the execution of any real world task. In this work, we have investigated the task of opening a door in a hot-cell i.e. high radiation environment with the specified objective of safe completion of task without using a force torque sensor. For this, a compliance control methodology has been formulated which generates both position path and force profile for the task undertaken. The control action employed in the current approach involves position and force control of the manipulator in mutually orthogonal directions viz., radial and tangential directions to the centre of rotation of the door. The kinematic parameters required for such tasks are position of the door’s knob and its hinge. The performance of the control algorithm has been tested on a simulated generic robot dynamic model. Firstly, the algorithm and control action was tested for the task of opening the door whose kinematics was known a priori and eventually tested for the task where the prior knowledge of the door kinematics and hinge position was not known.

Industrial robots are required to interact with the surrounding environment to perform a given task (e.g., an assembly task). However, standard industrial robots are commonly position-controlled. Therefore, there is the need to implement an outer compliance controller to guarantee a safe interaction. Such compliance controllers require force/torque measurements to close the loop, and most of the industrial manipulators available on the market do not have embedded force/torque sensor(s), requiring additional efforts (i.e., additional costs and implementation resources) for such integration in the robotic setup. To provide a standard industrial sensorless position-controlled robot with the capabilities to execute an interaction task, the proposed paper defines an external joint torques observer for the implementation of an outer sensorless compliance controller. More in detail, exploiting the resulting position-controlled robot dynamics, an Extended Kalman Filter (EKF) is proposed to estimate the external joint torques. Exploiting such an estimation, an outer impedance controller can be designed, providing a position/velocity reference to the inner position controller. The described approach has been validated with experiments on a Franka EMIKA panda robot. A human operator interacts with the controlled robot, applying external wrenches (i.e., both Cartesian forces and torques). The resulting external joint torques are estimated making use of the proposed EKF, comparing the achieved results with the signals provided by the joint torque sensors of the Franka EMIKA panda robot (measurements used as a baseline for validation purposes). Experimental results show the capabilities of the proposed control framework in estimating the applied external joint torques while implementing a position control-based compliance controller.

Compliant force control in space docking is studied. Compliant force control strategy is developed based on the inner loop position control of 6-dof parallel robot in order to simulate push and pull process of forcible alignment in space docking. Compliant force control structure based on the inner position loop is introduced. The more systematic design methods of a serial PID type controller and a robust controller are presented in detail. Simulation and experiment results indicate efficiency of the designed force controllers and superiority of robust force controller.

This paper presents a model and controller design for a pneumatic actuator system. Three control strategies of position, force and compliance control are proposed. From the compliance control, stiffness characteristic of the pneumatic actuator will be presented in real-time system. Model of the pneumatic actuator system (transfer function) is obtained from System Identification (SI) method. Next, Predictive Functional Control (PFC) with observer design is selected as the control strategy for the pneumatic system. Performance assessment of the controller is performed in MATLAB and validated through real-time experiment. Result shows that the PFC controller is adapted to the system and able to control successfully in both simulation and experiment.

The best exoskeleton control strategy depends on the task, motivating the development and analysis of an exoskeleton capable of position, force, and impedance control. In this paper, we implement and compare the three controller types via sliding mode control on a custom-built pneumatic cylinder ankle exoskeleton. To evaluate each controller's performance, the exoskeleton was tested on the benchtop and with human subject experiments. With the position controller, the exoskeleton achieved an root-mean-square error (RMSE) of under 5 deg for both the benchtop and human tests. It had a bandwidth of approximately 12 rad/s. The force controller tracked sinusoidal trajectories acceptably well at low frequencies (15% of force range at 6 rad/s), with a bandwidth of approximately 24 rad/s. The error was significantly higher (RMSE of 24% of force range) for the more biologically relevant trajectory. The impedance controller demonstrated the desired spring-like behavior, with position RMSE generally under 5 deg compared to expected position. All three controllers worked equally well for benchtop and human tests. Thus, a pneumatically powered ankle exoskeleton with sliding mode control is capable of accurate position and impedance control and is capable of marginally acceptable force control.

In this paper, model-based precision force and position control of an ionic polymer metal composite (IPMC) is presented. A 23.8 mm × 3.4 mm × 0.16 mm IPMC strip was used as an actuator in a cantilever configuration. Open-loop force and position responses of an IPMC are not repeatable, and hence closed-loop precision control is of critical importance to ensure proper functioning, repeat-ability and reliability. After feedback controllers were designed and implemented with empirically obtained fourth-order plant transfer functions, the overshoot decreased from 460 to 2.8 per cent and the settling time was reduced from 37.5 to 3.22 s in force control. In position control the overshoot decreased from 333 to 20.3 per cent and the settling time was reduced from 21.5 to 2.56 s. Microscale precision force and position control capabilities of the IPMC actuator were also demonstrated experimentally. An 8 μN force resolution was achieved with a force noise of 0.5μN r.m.s., and the position resolution was 6 μm with a position noise of 2.5 μm r.m.s. The maximum force and tip displacement achieved with the IPMC actuator under closed-loop control were 2 mN and 5 mm respectively. The IPMC actuator could follow various commanded force and position trajectories such as sinusoidal and trapezoidal position profiles, and a velocity profile with a 3 mm/s maximum velocity. A novel hybrid force and position control strategy demonstrated its utility in practical micromanipulalion applications where the actuator force must be limited to prevent damaging micro-objects. High-precision control of the IPMC at low force level proved its potential for micromanufacturing and micromanipulation applications such as robotic and biomedical microgrippers.

Robots have entered human life, and closer relationships are being formed between humans and robots. It is desirable that these robots be flexible and lightweight. For this reason, we studied and developed an artificial muscle actuator using straight-fiber-type artificial muscles derived from the McKibben-type muscles, which have excellent contraction rate and force characteristics. However, these muscles have highly nonlinear characteristics, as well as high compliance and a strong hysteresis characteristic. Hence, it is difficult to control the artificial muscle manipulator. In this study, a mechanical equilibrium model is introduced to control this manipulator, and the position control characteristic is linearized, making compliance control possible. In addition, considering dynamic characteristics of the artificial muscle, we apply an “inner model control” for position control.

Automatic cell injection has been the focus of many researches and commercial development for several years. In this paper, a robotic cell injection system for automatic batch injection of suspended cells is developed. To facilitate the process, these suspended cells are held and fixed to a cell array by a specially designed cell holding device, and injected one by one through an “out-of-plane” cell injection process. A micropipette equipped with a PVDF micro force sensor is integrated in the proposed system. The force sensor is utilized to measure real time injection force applied to the cells during injection process. Through calibration of the relationship between the cell injection force and the desired injector pipette trajectory, a position (vision) and force control algorithm is proposed and applied to the motion control of the injection pipette in three-coordinate directions during an injection process. The out-of-plane cell injection task is decoupled into a position control in X-Y horizontal plane and an impedance force control in Z-axis. The depth motion of the injector pipette, a common problem of three-dimensional micromanipulation, is indirectly controlled by the force control. Finally, experimental results are given to demonstrate the effectiveness of the proposed approach.

42 - Neural Network and Fuzzy Logic Systems: Techniques and Applications in Telerobot Systems

Two different control schemes, position model referenced control (PMRC) and force model referenced control (FMRC), are developed for a simplified two robots model with one interacting axis. The dynamic stability of the position (or force) control under the FMRC (or PMRC) is analyzed. Results indicate that PMRC, although providing better dynamic performance of the position control, may degrade the dynamic performance of the force control. However, FMRC can provide better dynamic performance of both position and force control.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

To address the demands for precision and load-bearing capacity in the installation of building panels, a hybrid force-position driven robot with redundant actuation has been developed. The mechanical performance of this robot is primarily governed by its central parallel mechanism, which is equipped with redundant actuators matching the degrees of freedom. Non-redundant and redundant actuators are respectively responsible for position and force control. The inclusion of redundant force-driven joints has increased the internal coupling within the mechanism. To enhance the coordination between position and force control, a hybrid synchronized control method based on cross-coupling has been proposed. Initially, kinematic and dynamic models of the parallel structure were established. Under predefined trajectories, the theoretical inputs for each actuator were calculated using inverse kinematics and dynamics. Subsequently, employing the principle of cross-coupling, the torque output from the position actuators was used as feedback. This feedback was processed by a synchronized coordination controller to adjust the output force of the redundant force-driven joints. By adjusting the output force of the redundant actuators, the torque burden on the position actuators was effectively reduced, thereby enhancing the precision of position control. Additionally, under the same load conditions, smaller power actuators could be utilized for position control, reducing the overall weight of the robot and improving its load-to-weight ratio. To validate the effectiveness of the proposed control strategy, a robotic simulation environment was established. The simulation results demonstrated significant reductions in the average torque required by the position actuators across three different trajectories, with reductions of 91.43%, 54.56%, and 80.6% respectively. Finally, the load-bearing capacity and the load-to-weight ratio of the prototype were assessed. Experimental results confirmed that the prototype achieved a load-to-weight ratio of 15.83%, validating the effectiveness of the hybrid synchronized control method based on cross-coupling.