Kinematics and cooperative control of a robotic spinal surgery system

Robotica ◽  
2014 ◽  
Vol 34 (1) ◽  
pp. 226-242 ◽  
Author(s):  
Haiyang Jin ◽  
Ying Hu ◽  
Wei Tian ◽  
Peng Zhang ◽  
Zhangjun Song ◽  
...  

SUMMARYSpinal surgery is considered a high-risk surgery. To improve the accuracy, stability, and safety of such operations, we report the development of a novel six-degrees-of-freedom Robotic Spinal Surgical System that can assist surgeons in performing transpedicular surgery, one of the most common spinal surgeries. After optimization performed using Response Surface Methodology, the largest available workspace of the robot is determined and is found to easily cover the entire operation area. Cooperative control and navigation-based active control are implemented for different processes of the operation. We propose a hybrid control approach based on the speed and torque interface at the joint level. In this mode, the robot is compliant in Cartesian space, benefitting both the accuracy and efficiency of the operation. A comprehensive assessment index, combining the subjective and objective criteria in terms of positioning and operation efficiency, is proposed to compare the performance of cooperative control in speed mode, torque mode, and hybrid control mode. Active fine adjustment experiments are carried out to verify the positioning accuracy, and the results are found to satisfy the requirements of operation. As an application example, a pedicle screw insertion experiment is performed on a pig vertebral bone, demonstrating the effectiveness of our system.

1990 ◽  
Vol 112 (4) ◽  
pp. 653-660 ◽  
Author(s):  
H. Kazerooni ◽  
K. G. Bouklas ◽  
J. Guo

This work presents a control methodology for compliant motion in redundant robot manipulators. This control approach takes advantage of the redundancy in the robot’s degrees of freedom: while a maximum six degrees of freedom of the robot control the robot’s endpoint position, the remaining degrees of freedom impose an appropriate force on the environment. To verify the applicability of this control method, an active end-effector is mounted on an industrial robot to generate redundancy in the degrees of freedom. A set of experiments are described to demonstrate the use of this control method in constrained maneuvers. The stability of the robot and the environment is analyzed.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Bohang Wang ◽  
Daobo Wang

In this article, a new and novel robust hybrid control algorithm is designed for tuning the parameters of unmanned aerial vehicle (UAV). The quadrotor type UAV mathematical model is taken to observe the effectiveness of our designed robust hybrid control algorithm. The robust hybrid control algorithm consists of H∞ based regulation, pole-placement and tracking (RST) controller along with mixed sensitivity function is applied to control the complete model of UAV. The selected rotor craft is under-actuated, nonlinear and multivariable behavior in nature along with six degrees of freedom (DOF). Due to all these aforementioned issues its stabilization is quite difficult as compared to fully actuated systems. For the tuning of nonlinear parameters of the UAV, we designed, robust hybrid control algorithm is used. Moreover, the performance of the designed controller is compared with robust controller. The validity and effectiveness of the designed controllers are simulated in MATLAB and Simulink, in which the designed controller shows better steady state behavior, robustness and converges quickly in specific amount of time as compared to robust controller.


Author(s):  
A. R. Plummer

A practical motion control method is presented for multiaxis parallel servohydraulic mechanisms in which the payload behaves as a rigid mass. The ability of this method to decouple the control axes is demonstrated. A modal control approach is used – i.e. the modes of vibration of the system are controlled individually. These modes are dependent on the inertial properties of the payload and the compliance of the actuators due to oil compressibility. For each mode, a partial non-linear dynamic inversion is performed in the control loop. To avoid the need to differentiate the position feedback signals, accelerometers are also used, and three-element motion state vectors are estimated using composite filtering. Command feedforward is used to increase the tracking bandwidth, and the closed-loop part of the controller can be conceived as a model-based disturbance observer. Simulation results are presented based on a detailed validated model of a large vibration table used for earthquake simulation. Just three of the six degrees-of-freedom of the table are considered, and the results for horizontal acceleration tracking response are presented, along with the ability of the controller to reject the ‘overturning moment’.


1995 ◽  
Vol 7 (1) ◽  
pp. 69-74
Author(s):  
Toshiro Noritsugu ◽  
◽  
Hiroyuki Inoue ◽  

The present autonomous control robots are technically difficult to introduce into unknown working environments. A cooperative control approach between human and robot may be an effective approach for complex and uncertain tasks. This study develops a new cooperative control approach between human and robot by using a fuzzy reasoning and handles force control under the uncertain working environments. The proposed control approach can achieve three control modes: manual, cooperative, and autonomous control, one of which can be automatically chosen by the operator through fuzzy reasoning. Fuzzy reasoning receives two inputs from the operator and the robot. By introducing the fuzzy reasoning, the various human skills can be introduced into cooperative control and can integrate an intuitive human control and a precise autonomous robot control. Some contacting tasks are executed for various object walls using a two-degrees of freedom Cartesian robot. The results indicate the availability of the proposed control approach.


2020 ◽  
pp. 67-73
Author(s):  
N.D. YUsubov ◽  
G.M. Abbasova

The accuracy of two-tool machining on automatic lathes is analyzed. Full-factor models of distortions and scattering fields of the performed dimensions, taking into account the flexibility of the technological system on six degrees of freedom, i. e. angular displacements in the technological system, were used in the research. Possibilities of design and control of two-tool adjustment are considered. Keywords turning processing, cutting mode, two-tool setup, full-factor model, accuracy, angular displacement, control, calculation [email protected]


Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3740
Author(s):  
Olafur Oddbjornsson ◽  
Panos Kloukinas ◽  
Tansu Gokce ◽  
Kate Bourne ◽  
Tony Horseman ◽  
...  

This paper presents the design, development and evaluation of a unique non-contact instrumentation system that can accurately measure the interface displacement between two rigid components in six degrees of freedom. The system was developed to allow measurement of the relative displacements between interfaces within a stacked column of brick-like components, with an accuracy of 0.05 mm and 0.1 degrees. The columns comprised up to 14 components, with each component being a scale model of a graphite brick within an Advanced Gas-cooled Reactor core. A set of 585 of these columns makes up the Multi Layer Array, which was designed to investigate the response of the reactor core to seismic inputs, with excitation levels up to 1 g from 0 to 100 Hz. The nature of the application required a compact and robust design capable of accurately recording fully coupled motion in all six degrees of freedom during dynamic testing. The novel design implemented 12 Hall effect sensors with a calibration procedure based on system identification techniques. The measurement uncertainty was ±0.050 mm for displacement and ±0.052 degrees for rotation, and the system can tolerate loss of data from two sensors with the uncertainly increasing to only 0.061 mm in translation and 0.088 degrees in rotation. The system has been deployed in a research programme that has enabled EDF to present seismic safety cases to the Office for Nuclear Regulation, resulting in life extension approvals for several reactors. The measurement system developed could be readily applied to other situations where the imposed level of stress at the interface causes negligible material strain, and accurate non-contact six-degree-of-freedom interface measurement is required.


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