WO2020156414A1

WO2020156414A1 - A compact dental robotic system

Info

Publication number: WO2020156414A1
Application number: PCT/CN2020/073738
Authority: WO
Inventors: Zheng Wang; Jing Li; Zhong SHEN; Yu Hang Walter LAM; Tai Chiu Richard HSUNG; Ho Nang Edmond POW
Original assignee: The University Of Hong Kong
Priority date: 2019-01-31
Filing date: 2020-01-22
Publication date: 2020-08-06
Also published as: CN113365572A; CN113365572B

Abstract

A robotic manipulator system (300) and method for performing dental operations are provided. The robotic manipulator system (300) includes a robotic manipulator (305) configured to perform dental operations, a plurality of motors (315), a tendon-sheath transmission system (310) configured to actuate at least the robotic manipulator (305), an imaging system (371, 372) configured to monitor the dental operations, and a control system (320) coupled to the plurality of motors (315) configured to control motions of the robotic manipulator (305) for performing the dental operations. The robotic manipulator system (300) can be employed for dental drilling procedures and has a dimension and workspace that are twice smaller than a conventional robotic dental drilling system.

Description

A COMPACT DENTAL ROBOTIC SYSTEM

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 62/799,460, filed January 31, 2019, which is hereby incorporated by reference in its entirety including any tables, figures, or drawings.

BACKGROUND OF THE INVENTION

Dental issues are quite common in the daily life and can be extremely severe and painful, affecting life quality and systemic health [4] if patients cannot get appropriate treatments in time.

However, global labor shortage in dentistry has made timely treatments impossible for most patients. Therefore, applying robots to dental procedures has been proposed. With the controllable motions, robots can not only improve the efficiency of dental procedures, but also improve the treatment efficacy by preventing human errors since most dental procedures are fully dependent on dentists’ manual skills [6] .

Robots being used in dentistry can be generally divided into two categories [7, 8] , one for training purposes by simulating human reactions during the dental treatments [9-12] , and the other for assisting dental procedures [13-16] . For the latter one, multiple designs have been proposed for different dental procedures [17, 18] , among which, Yomi, released by Neocis Company and the dental robot developed [19] are the most advanced ones. Yomi was approved by FDA last year and is targeted at dental implants surgeries. With its navigating system, Yomi is able to provide a physical guidance for dentists to the precise localization of the tooth needing repair. The dental robot proposed [19] has performed a clinical trial of dental implant surgery, where the robotic manipulator is able to locate the dental caries automatically.

Both of these manipulators were adapted from current industrial manipulators, whose dimensions as well as workspaces are too large to be used for dental applications [20] .

One main challenge in designing robotic system for dental applications is the unavoidable elongation of tendons that brings vibrations at the end, which will affect the performances especially when precision and steadiness are both required. Undesirable vibrations usually occur during robot operations due to the compliance between joint connections, especially for manipulators with multiple degrees of freedom. For tasks requiring precision, it takes extra time waiting for the vibration to be damped out which limits the force and position control [21] at the end-effector. It became worse for machining and drilling procedures, where the vibratory load could excite a resonance if the lowest natural frequency is not sufficiently higher than the load vibrating frequency.

BRIEF SUMMARY OF THE INVENTION

There continues to be a need in the art for improved designs and techniques for a robotic system for relieving burdens of the dentists, improving the efficiency of the dental procedures, and reducing human errors during the treatments..

Embodiments of the subject invention pertain to a robotic manipulator system and methods for performing dental operations.

According to an embodiment of the subject invention, a robotic manipulator system for performing dental operations can comprise a robotic manipulator configured to perform dental operations; a plurality of motors; a tendon-sheath transmission system configured to actuate at least the robotic manipulator; an imaging system configured to monitor the dental operations; a control system coupled to the plurality of motors configured to control motions of the robotic manipulator for performing the dental operations. The robotic manipulator comprises a plurality of robotic arms, a plurality of joints connecting adjacent robotic arms of the plurality of robotic arms, and an end-effector disposed at a distal end of the robotic arms. The tendon-sheath transmission system can be configured to connect the plurality of motors to the plurality of joints. The plurality of joints can comprise two revolute joints, two cylindrical joints and one wrist joint with two joints crossed. Moreover, the robotic manipulator is configured to have a plurality of freedom in motions. The robotic manipulator system can further comprise a haptic device coupled to the controller for teleoperation. The haptic device can be configured to provide an end position of the haptic device in real time to the control system such that the robotic manipulator is configured to move by the motors in a same trajectory as that of the haptic device. Furthermore, the imaging system can comprise a plurality of image capturing devices.

In certain embodiment of the subject invention, a method is provided for controlling a robotic manipulator system that comprises a robotic manipulator having a plurality of robotic arms, an end-effector, and a plurality of joints configured to perform dental operations, a plurality of motors, a tendon-sheath transmission system configured to actuate at least the robotic manipulator, an imaging system configured to monitor the dental operations, acontrol system configured to control motions of the robotic manipulator for performing the dental operations. The method can comprise controlling, by the controller, sequential motions of the plurality of motors which drive the joints to generate motions of the end-effector to perform the dental operations. The controlling can comprise calculating resolution of joint angle and continuous output torque of the joints, calculating motion and force transmission of the robotic manipulator, or calculating position accuracy of the robotic manipulator in three dimensions based on relations between the joint angles. Transformation matrixes can be generated based on Denavit-Hartenberg (DH) parameters and a position of distal joint of the joints is computed by multiplying the transformation matrixes in order. Position and orientation of end-effector of the robotic manipulator is obtained by sensors generating position mapping in teleoperations for the robotic manipulator system. Moreover, the robotic manipulator system can further comprise a slave system comprising motors and a plurality of robotic arms replicates motions of the robotic manipulator system based on the position mapping in a Cartesian coordinate system. The joint angles can be converted to motor angles based on the resolution of each motor and the relation between the motor angle and the joint angle measured. When the motors are set to a velocity control mode, the velocities of the motors are determined by differences between target motor angles and real motor angles and are processed by predetermined motion controlling mechanism. The robotic manipulator system can further comprise a haptic device coupled to the controller for teleoperation, wherein only when a wrist point of the haptic device is moved into a predetermine space, a position and orientation of an end of haptic device is determined to be valid and converted to nonzero velocity instructions for the motors to move the robotic manipulator; otherwise, the robotic manipulator remains stationary.

BRIEF DESCRIPTION OF THE DRAWINGS

Figures 1A and 1B are schematic diagrams of an unconstrained robotic manipulator system and a robotic manipulator system operating against a work surface, respectively, according to prior art.

Figure 2 is a schematic representation of a robotic system coupled to a dentist’s console for operating on teeth of a human oral cavity according to an embodiment of the subject invention.

Figure 3A is a schematic representation of the abstract coordinate frames of the robotic manipulator system according to an embodiment of the subject invention.

Figure 3B is a schematic representation of the specific design of the robotic manipulator system, showing how the joint is connected to the motor, according to an embodiment of the subject invention.

Figure 4 shows the coordinate system of the workspace of the robotic manipulator of the robotic system based on a kinematics analysis according to an embodiment of the subject invention.

Figures 5A and 5C are side views of a pair of tendons connecting the inner part and the outer part of a cylindrical joint and actuate rotations in clockwise and counterclockwise directions, respectively, according to an embodiment of the subject invention.

Figure 5B is a side view of a revolute joint rotating around the shaft perpendicular to both its distal and proximal end according to an embodiment of the subject invention.

Figure 5D is a side view showing the tendon-sheath system of the wrist joint according to an embodiment of the subject invention.

Figure 5E is a side view of the tendon-sheath mechanism of the robotic manipulator system, showing how the joint is connected to the motor, according to an embodiment of the subject invention.

Figures 6A and 6B show prototypes of a binocular display and cameras of an imaging system of the robotic system, respectively, according to an embodiment of the subject invention.

Figure 6C is a plot diagram showing the scheme of the imaging system according to an embodiment of the subject invention.

Figure 7 is a schematic diagram of a control method and configurations of the robotic system according to an embodiment of the subject invention.

Figure 8A is a schematic diagram of the configuration of the robotic system according to an embodiment of the subject invention.

Figure 8B is a schematic diagram of trajectories of an end-effector of the robotic manipulator and a haptic device of the dentist’s console after mapping according to an embodiment of the subject invention.

Figure 8C is a schematic diagram of the configuration of the haptic device according to an embodiment of the subject invention.

Figure 9A shows a prototype of the robotic manipulator integrated with the imaging system according to an embodiment of the subject invention.

Figure 9B shows a left eye view of the dental drill of the robotic manipulator operating on teeth according to an embodiment of the subject invention.

Figure 9C shows a right eye view of the dental drill of the robotic manipulator operating on teeth according to an embodiment of the subject invention.

Figure 10 is a plot diagram of experimental results of motion and force transmission tests of the first four joints of the robotic manipulator according to an embodiment of the subject invention.

Figure 11 is a plot diagram showing relationships between input torque and output torque based on the results of the first four joints of Figure 10 according to an embodiment of the subject invention.

DETAILED DISCLOSURE OF THE INVENTION

System Design and Analysis

A. System Design

Referring to Figure 2, the robotic system 300 can comprise a robotic manipulator 305 of a plurality of, for example, six, degrees of freedom (DOF) and having an end-effector 365 such as a dental drill, a tendon-sheath transmission system 310 configured to actuate at least the robotic manipulator 305, a motor set 315 having a plurality of, for example, six, motors for motion control, and a controller 320 coupled to the plurality of motors configured to control motions of the robotic manipulator 305 for performing the dental operations. The robotic system 300 can be coupled to a dentist console 330 that comprise an imaging system 371/372 connected to a stent 350, a stereo display 335 connected to the stent 350, and a haptic device 340 for teleoperation.

As illustrated in Figure 2, the robotic manipulator 305 can comprise a plurality of robotic arms connected by a plurality of joints that is 3D printed by plastic filaments (PLA+) . Motors 315 such as motors provided by DYNAMIXIEL are coupled to the joints by the tendon-sheath system 310 and each motor 315 can be connected to one joint. Through the tendon-sheath system 310, the actuation part can be moved away from the joints, therefore the scale and weight of the robotic system 300 can be greatly decreased, and so is the workspace.

Moreover, during the dental procedures, a dentist can hold the haptic device 340 such as a touch 3D stylus providing its end position in real time to the controller 320 such that the robotic manipulator 305 is moved in a same trajectory as that of the haptic device 340 when the controller 320 sends appropriate instructions to the motors 315.

B. Kinematics Analysis

The robotic manipulator 305 can comprise a plurality of joints, for example, six joints including two revolute joints, two cylindrical joints and one wrist joint with two joints crossed. Detailed mechanical design specifications are shown in table II.

The resolution of joint angle as well as the joint continuous output torque is calculated according to the technical specifications of the motors such as motors of DYNAMIXEL MX series and PRO series. The motion and force transmission results are considered and converted as well.

The position accuracy is calculated in three dimensionsΔx, Δy, andΔz, according to their relations between joint angles. The steel wires elongation is estimated by calculating the elastic elongation of steel wires having a total length, for example, 350 mm, a diameter, for example, 0.68 mm, and under a load, for example, 300g. Both of these results are shown in Table II and Denavit-Hartenberg (DH) parameters are listed in Table I.

Table I

Table II

In one embodiment, transformation matrixes can be written according to the DH parameters and the position of the last joint can be computed by multiplying these transformation matrixes in order. The DH parameters are four parameters associated with a particular convention for attaching reference frames to the links of a spatial kinematic chain, which has been widely used in kinematic analysis of manipulators.

Figure 3A is a schematic representation of the abstract coordinate frames of the robotic manipulator system and Figure 3B is a schematic representation of the specific design of the robotic manipulator system, showing how the joint is connected to the motor. As illustrated in Figure 3A, it is assumed that the starting point is (0, 0, 0, 1) ^Tlabeled as (x ₀, y ₀, z ₀) and the center position of the last joint is obtained by following equations:

x ₆=cθ ₁(l ₃cθ ₂+l ₄sθ ₂₊₃) (1)

y ₆=sθ ₁(l ₃cθ ₂+l ₄sθ ₂₊₃) (2)

z ₆=l ₄cθ ₂₊₃-l ₃sθ ₂+l ₀ (3)

Regarding inverse kinematics analysis, the position and orientation of the 6 ^th joint is assumed to be (x ₆, y ₆, z ₆, α ₆, β ₆, γ ₆) , through which the angles of each joint can be calculated. Since the last three joints intersect with each other, the location of the last joint only relates to the first three joints. And the results can be calculated based on following equations.

Where z ₆′=z ₆-l ₀, sθ=sinθ, cθ=cosθ.

The rest of the joint angles can be calculated based on the rotational transformation matrix

which can be computed according to

Based on the kinematics analysis, the workspace of the manipulator 305 is plotted as shown in Figure 4, where the angle ranges of the cylindrical joints are 90 degrees, for the rest joints are half of its full rotational range. Moreover, a human tooth sketch is plotted in Figure 4, which can be fully covered by the workspace of the dental drill 365 mounted on the robotic manipulator 305.

C. Tendon-sheath System

The tendon-sheath system 310 has been widely used in surgical robots, especially in laparoscopic surgeries, where space constrains can be greatly relieved by moving actuation parts away. The tendon-sheath system 310 of the embodiments of the subject invention offers advantages including manipulation flexibilities in the dental procedures.

Structures of joints are designed based on their motion features. Therefore, in the embodiments of the subject invention there are three types of joints, namely, a cylindrical joint, a revolute joint and a wrist joint.

Each cylindrical joint comprises two parts, an outer part and an inner part which rotates along a center shaft and transfers rotatory motions to its proximal joints. As shown in Figures 5A and 5C, a pair of tendons is employed to connect these two parts and actuate rotations in clockwise or counterclockwise directions.

The revolute joint as shown in Figure 5B rotates around the shaft perpendicular to both its distal and proximal ends. A pair of tendons is placed mirror symmetrically passing through the holes in the distal and proximal ends and the other revolute joint differs only in size.

The wrist joint is designed based on a universal joint. The two ends of the universal joint are fixed to two separate parts and are connected with a plurality of, for example, four, wires, one for each direction. In order to inhibit the interferences between wires crossed in between, the moving trajectories of the wires are restricted to a sphere whose center is the same as that of the universal joint. When one wire is stretched, the other wire opposite to it will be loosened, while the crossed ones will not be affected since the motion generated is along the surface perpendicular to them.

Figure 5D is a side view showing the tendon-sheath mechanism of the wrist joint and Figure 5E is a side view of the tendon-sheath mechanism of the robotic manipulator system showing how the joint is connected to the motor, according to an embodiment of the subject invention.

D. Imaging System

Referring to Figures 6A and 6B, the imaging system can comprise two imaging devices such as cameras 371/372 positioned close to the teeth and a stereo display 335 such as a binocular display for a dentist to monitor the locating and drilling process during the dental procedures. The distance between the two displays of the binocular display 335 can be adjusted in order to make pupil distance fit for different users of the imaging system.

E. Control and System Integration

The control method and the configuration of the robotic system 300 including the teleoperation part are illustrated in Figure 7.

The haptic device 340 can comprise a plurality of, for example, six, degrees of freedom, and the position and orientation of its end-effector can be obtained through built-in sensors for position mapping of teleoperations for the robotic system 300.

The configuration of the haptic device 340 is shown in Figure 8C, while the configuration of the robotic manipulator 305 is shown in Figure 8A.

Referring to Figure 8B, based on the position mapping in a Cartesian coordinate system, a slave system that includes motors and a plurality of robotic arms can replicate the motions of the master system containing the haptic device 340 which is operated by the dentist. The dentist can adjust his/her motions based on the visual feedback from the stereo imaging system.

Instead of exhausting the whole workspace of the haptic device, only a cubic-shaped volume marked as a blue box in Figure 8C is chosen to map to a similar cubic-shaped volume marked as a red box in Figure 8A of the manipulator workspace.

Only when the wrist point of the haptic device 340 is moved into the chosen cubic volume, the position and orientation of its end will be determined to be valid and converted to nonzero velocity instructions for motors; otherwise, the robotic system 300 will stay in place.

The coordinate system employed is rotated and the origin is translated in order to match the configurations of the manipulator 305. The motions are scaled down by multiplying a factor k _p which is smaller than one with the displacement between neighboring positions of the haptic device 340, while the orientations are multiplied by another factor k _θ. Confined motions as well as preserved orientations can be realized by adjusting these two scaling factors. The converted locations and orientations after mapping are combined for the inverse kinematics analysis, before which, a boundary test is performed for limiting the final position of the end-effector of the robotic arm within a small range.

Figure 8B shows the trajectories of the end-effector and the haptic device 340 after mapping.

Joint angles are then converted to motor angles based on the resolution of each motor and the relation between the motor angle and joint angle measured in motion transmission experiments. When the motors are set to a velocity control mode, the velocities of which are determined by the differences between target motor anglesγand real motor anglesγ′and are processed with appropriate motion control.

The robotic manipulator integrated with the imaging system is shown in Figure 9A. Diameters of the two cameras can be, for example, 5.5 mm, and the focal lengths of the two cameras can be, for example, 20 mm, which is suitable for human oral cavity. The light intensity of LEDs integrated with the cameras can be adjusted, making it more convenient for the dental procedures. As illustrated in Figure 9A, the cameras are fixed to a stent while the robotic manipulator can move freely.

Experimental Validation of the Motion and Force Transmission

The relationships between motor angles and joint angles are measured. The experimental results of the first four joints are shown in Figure 10. It can be seen that the relationships between the motor angles and joint angles can be fitted well with linear relationships and the coefficients differ due to the different diameters of the mounting parts for the motors and different dimensions of thejoints.

In one embodiment, for cylindrical joints, the diameter of the mounting parts can be set to be, for example, 36 mm, while for revolute joints and wrist joints, the diameters can be set to be, for example, 12 mm. In order to increase the positioning accuracy and output payload with a consideration of the space limitations, the diameters of the revolute joints along the rotational directions can be set to be, for example, 50 mm and 60 mm, respectively, 47 mm and 27 mm for the two cylindrical joints, respectively, and 80 mm for the wrist joint. The ratio differences can be observed from the motion transmission measurement results as well.

The relationships between input torque and output torque are measured in the same manner. The results of the first four joints are shown in Figure 11 when the speed ratios between motors and joints are considered and converted. Therefore the data reflects the energy loss owing to the friction between the tendon and the sheath. It is also observed from the data obtained that around 50%of the input torque is lost during the transmission.

The robotic system of the subject invention is provided for assisting dental drilling procedures, having a dimension and workspace that can be twice smaller than the conventional robotic dental drilling system. The dental robotic system of the subject invention is designed for relieving burdens of the dentists, improving the efficiency of the dental procedures, and reducing human errors during the treatments.

All patents, patent applications, provisional applications, and publications referred to or cited herein are incorporated by reference in their entirety, including all figures and tables, to the extent they are not inconsistent with the explicit teachings of this specification.

It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and the scope of the appended claims. In addition, any elements or limitations of any invention or embodiment thereof disclosed herein can be combined with any and/or all other elements or limitations (individually or in any combination) or any other invention or embodiment thereof disclosed herein, and all such combinations are contemplated with the scope of the invention without limitation thereto.

REFERENCES

[1] C. Global Burden of Disease Study, "Global, regional, and national incidence, prevalence, and years lived with disability for 301 acute and chronic diseases and injuries in 188 countries, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013, "Lancet, vol. 386, pp. 743-800, Aug 222015.

[2] N.J. Kassebaum, E. Bernabe, M. Dahiya, B. Bhandari, C.J. Murray, and W. Marcenes, "Global burden of severe periodontitis in 1990-2010: a systematic review and meta-regression, " J Dent Res, vol. 93, pp. 1045-53, Nov 2014.

[3] N.J. Kassebaum, E. Bernabe, M. Dahiya, B. Bhandari, C.J. Murray, and W. Marcenes, "Global burden of untreated caries: a systematic review and metaregression, " J Dent Res, vol. 94, pp. 650-8, May 2015.

[4] R.I. Garcia, M.M. Henshaw, and E.A. Krall, "Relationship between periodontal disease and systemic health, " Periodontology 2000, vol. 25, pp. 21-36, 2001.

[5] Health Facts of Hong Kong. Available: https: //www. dh. gov. hk/english/statistics/statistics_hs/files/Health_Statistics_pamphlet_E. pdf

[6] D. Ericson, E. Kidd, D. McComb, I.

and M. Noack, Minimally Invasive Dentistry-concepts and techniques in cariology vol. 1, 2003.

[7] D.P. Kumar PY, Kalaivani V, Rajapandian K.J "Future Advances in Robotic Dentistry, " DentHealth OralDisord Ther vol. 7 (3) : 00241., 2017.

[8] M. Rawtiya, K. Verma, P. Sethi, and K. Loomba, Application of Robotics in Dentistry Quick Response Code vol. 6, 2014.

[9] T. Tanzawa, K. Futaki, H. Kurabayashi, K. Goto, Y. Yoshihama, T. Hasegawa, et al., "Medical emergency education using a robot patient in a dental setting, " Eur J Dent Educ, vol. 17, pp. e114-9, Feb 2013.

[10] T. Tanzawa, K. Futaki, C. Tani, T. Hasegawa, M. Yamamoto, T. Miyazaki, et al., "Introduction of a robot patient into dental education, "Eur J Dent Educ, vol. 16, pp. e195-9, Feb 2012.

[11] H. Takanobu, A. Takanishi, and I. Kato, "Design of a mastication robot mechanism using a human skull model, " in Proceedings of 1993 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS'93) , 1993, pp. 203-208 vol. 1.

[12] H.U. Takanobu and A. Takanishi, "Dental robotics and human model, " in First International IEEE EMBS Conference on Neural Engineering, 2003. Conference Proceedings., 2003, pp. 671-674.

[13] Z.S. Haidar, Autonomous Robotics: A fresh Era of Implant Dentistry…is a reality! vol. 6,2017.

[14] Lam, W.Y., Hsung, R.T., Choi, W.W., Luk, H.W., &Pow, E.H. (2016) . A 2-part facebow for CAD-CAM dentistry. The Journal of prosthetic dentistry, 116 (6) , 843-847.

[15] Lam, W.Y., Hsung, R.T., Choi, W.W., Luk, H.W., Cheng, L.Y., &Pow, E.H. (2018) . A clinical technique for virtual articulator mounting with natural head position by using calibrated stereophotogrammetry. The Journal of prosthetic dentistry, 119 (6) , 902-908.

[16] Lam, W.Y., Hsung, R.T., Cheng, L.Y., &Pow, E.H. (2018) . Mapping intraoral photographs on virtual teeth model. Journal of dentistry, 79, 107-110.

[17] K. Gwangho, S. Hojin, I. Sungbeen, K. Dongwan, and J. Sanghwa, "A study on simulator of human-robot cooperative manipulator for dental implant surgery, "in 2009 IEEE International Symposium on Industrial Electronics, 2009, pp. 2159-2164.

[18] J. Jiang and Y. Zhang, "Application of robot to tooth-arrangement and dental implantology, "Jiqiren (Robot) , vol. 34, pp. 634-640, 2012.

[19] "First-ever robot-led dental surgery performed in China, "in Dental Tribune, ed. United Kingdom 2017.

[20] UR5 Technical specifications. Available: https: //www. aesculapusa. com/

[21] N. Delson and H. West, "Bracing to Increase the Natural Frequency of a Manipulator: Analysis and Design, "The International Journal of Robotics Research, vol. 12, pp. 560-571, 1993.

[22] L. Jae Young and W.J. Book, "Bracing micro/macro manipulators control, "in Proceedings of the 1994 IEEE International Conference on Robotics and Automation, 1994, pp. 2362-2368 vol. 3.

[23] W.J. Book, S. Le, and V. Sangveraphunsiri, "Bracing Strategy for Robot Operation, "in Theory and Practice of Robots and Manipulators: Proceedings of RoManSy’ 84: The Fifth CISM-IFToMM Symposium, A. Morecki, G. Bianchi, and K.

Eds., ed Boston, MA: Springer US, 1985, pp. 179-185.

[24] Z. Sun, Z. Wang, and S.J. Phee, "Elongation Modeling and Compensation for the Flexible Tendon--Sheath System, "IEEE/ASME Transactions on Mechatronics, vol. 19, pp. 1243-1250, 2014.

[25] T.N.T. Do, T. Tjahjowidodo, and S.J. Phee, "Dynamic Friction-Based Force Feedback for Tendon-Sheath Mechanism in NOTES System. "

[26] M. Khoshnam and R.V. Patel, "Tendon-sheath analysis for modeling and control of steerable ablation catheters, "in 2016 IEEE International Conference on Advanced Intelligent Mechatronics (AIM) , 2016, pp. 1585-1590.

[27] T.N. Do, T. Tjahjowidodo, M.W.S. Lau, T. Yamamoto, and S.J. Phee, "Hysteresis modeling and position control of tendon-sheath mechanism in flexible endoscopic systems, "Mechatronics, vol. 24, pp. 12-22, 2014/02/01/2014.

[28] J. Li, Z. Wang, Y.H.W. Lam, E.H.N. Pow, and T.C. Hsung, "A Customizable, Compact Robotic Manipulator for Assisting Multiple Dental Procedures, "in IEEE International Conference on Advanced Robotics and Mechatronics, ICARM2018, ed. Singapore: IEEE. , 2018, p. 1.

[29] J. Zhou, S. Chen, and Z. Wang, "A Soft-Robotic Gripper With Enhanced Object Adaptation and Grasping Reliability, "IEEE Robotics and Automation Letters, vol. 2, pp. 2287-2293, 2017.

[30] J. Zhou, J. Yi, X. Chen, Z. Liu, and Z. Wang, "BCL-13: A 13-DOF Soft Robotic Hand for Dexterous Grasping and In-Hand Manipulation, "IEEE Robotics and Automation Letters, vol. 3, pp. 3379-3386, 2018.

[31] P. Polygerinos, Z. Wang, K.C. Galloway, R.J. Wood, and C.J. Walsh, "Soft robotic glove for combined assistance and at-home rehabilitation, "Robotics and Autonomous Systems, vol. 73, pp. 135-143, 2015/11/01/2015.

[32] P. Polygerinos, Z. Wang, J.T.B. Overvelde, K.C. Galloway, R.J. Wood, K. Bertoldi, et al., "Modeling of Soft Fiber-Reinforced Bending Actuators, "IEEE Transactions on Robotics, vol. 31, pp. 778-789, 2015.

[33] Z. Wang, P. Polygerinos, J.T.B. Overvelde, K.C. Galloway, K. Bertoldi, and C.J. Walsh, "Interaction Forces of Soft Fiber Reinforced Bending Actuators, "IEEE/ASME Transactions on Mechatronics, vol. 22, pp. 717-727, 2017.

Claims

Arobotic manipulator system for performing dental operations comprising:

a robotic manipulator configured to perform dental operations;

a plurality ofmotors;

a tendon-sheath transmission system configured to actuate at least the robotic manipulator;

an imaging system configured to monitor the dental operations; and

a control system coupled to the plurality of motors configured to control motions of the robotic manipulator for performing the dental operations.
The robotic manipulator system of claim 1, wherein the robotic manipulator comprises a plurality ofrobotic arms, aplurality ofjoints connecting adjacent robotic arms of the plurality ofrobotic arms, and an end-effector disposed at a distal end ofthe robotic arms.
The robotic manipulator system of claim 2, wherein the end-effector is a drilling device.
The robotic manipulator system of claim 1 or claim 2, wherein the robotic manipulator is configured to have a plurality offreedom in motions.
The robotic manipulator system of any of claims 1-4, further comprising a haptic device coupled to the controller for teleoperation.
The robotic manipulator system ofclaim 5, wherein the haptic device is a touch 3D stylus.
The robotic manipulator system ofclaim 5 or claim 6, wherein the haptic device is configured to provide an end position ofthe haptic device in real time to the control system such that the robotic manipulator is configured to move by the motors in a same trajectory as that ofthe haptic device.
The robotic manipulator system of any of claims 1-7, wherein the imaging system comprises a plurality ofimage capturing devices.
The robotic manipulator system of any of claims 2-8, wherein the tendon-sheath transmission system is configured to connect the plurality ofmotors to the plurality ofjoints.
The robotic manipulator system of any of claims 2-8, wherein the plurality of joints comprises two revolute joints, two cylindrical joints and one wristjoint with two joints crossed.
Amethod for controlling a robotic manipulator system that comprises a robotic manipulator having a plurality of robotic arms, an end-effector, and a plurality of joints configured to perform dental operations, aplurality of motors, atendon-sheath transmission system configured to actuate at least the robotic manipulator, an imaging system configured to monitor the dental operations, acontrol system configured to control motions of the robotic manipulator for performing the dental operations, the method comprising:

controlling, by the controller, sequential motions of the plurality of motors which drive thejoints to generate motions ofthe end-effector to perform the dental operations.
The method of claim 11, wherein the controlling comprises calculating resolution ofjoint angle and continuous output torque ofthejoints.
The method of claim 11 or claim 12, wherein the controlling comprises calculating motion and force transmission ofthe robotic manipulator.
The method ofany ofclaims 11-13, wherein the controlling comprises calculating position accuracy of the robotic manipulator in three dimensions based on relationships between thejoint angles.
The method of any of claims 11-14, wherein transformation matrixes are generated based on DH parameters and a position ofdistal joint ofthe joints is computed by multiplying the transformation matrixes in order.
The method of any of claims 11-15, wherein position and orientation of the end-effector ofthe robotic manipulator is obtained by sensors that generates position mapping of teleoperations ofthe robotic manipulator system.
The method of claim 16, wherein the robotic manipulator system further comprises a slave system comprising motors and a plurality of robotic arms, motions of the slave system replicating motions of the robotic manipulator system based on the position mapping in a Cartesian coordinate system.
The method of any of claims 12-17, wherein the joint angles are converted to motor angles based on resolution ofeach motor and relationship between the motor angle and thejoint angle measured.
The method ofany ofclaims 12-18, wherein when the motors are set to a velocity control mode, the velocities ofthe motors are determined by differences between target motor angles and real motor angles and are processedby motion controlling mechanism.
The method of any of claims 11-19, wherein the robotic manipulator system further comprises a haptic device coupled to the controller for teleoperation, wherein only when a wrist point of the haptic device is moved into a predetermine space, aposition and orientation of an end of haptic device is determined to be valid and converted to nonzero velocity instructions for the motors to move the robotic manipulator; otherwise, the robotic manipulator remains stationary.