TASK 1: DESIGNING A LIGHT AND BACKDRIVABLE LINKAGE MECHANISM

• Approach:
  • The aim is to design a light, tight, low-friction, motor-linkage transmission system
  • Transmit motor power to robot link using a small gear 
  • For simplicity a two-loop transmission mechanism is designed

   

• The two-loop transmission
  • Gear loop (Motor shaft to gear wheel)
    • Motor power is transmitted to a large gear wheel using a timing belt to avoid slippage
    • Both motor shaft and gear wheel have timing teeth

     

  • Transmission loop (Gear wheel to linkage)
    • A flexible steel wire-based transmission
    • The wire is wrapped 1.5 times at each of  two terminal threaded wheels (60mm)
    • To avoid wire slippage the wire is retained using a jam screw in the threaded wheel
    • The wheel material is emptied to reduce weight whenever possible
    • Mechanism allows accessibility to jam screws of multiple gear wheels on a single shaft   

     

  • Testing
    • Mechanism is tested in lifting a payload of 3 Kgs without slippage
    • Ability to actuate the chain with moderate effort at both ends
    • Moderate backdrivability due to belt friction

               TASK 2: IMPROVED  BACKDRIVABILITY IN THE LINKAGE MECHANISM        

• Improved approach through experimentation
  • The aim is improve quality of motion and force display fidelity
  • To improve backdrivability the timing belt transmission in the first loop is dropped
  • To improve maintainability multiple loop mechanism to promote localized fault
  • A wire-based transmission is adopted to transmit motor power to gear wheel 
  • Multiple loop transmission using steel wire from motor to linkage

   

• Revision of the two-loop transmission
  • The gear loop (Motor shaft to gear wheel) (H-water-lifting-wire-disk-1D):
    • Motor power is transmitted to a large gear wheel using a tiff  wire drive system
    • A small threaded roller (14 turns) is attached to the motor shaft
    • The flexible wire is rolled 3 or 4 times on the motor roller (without retaining mechanism)
    • The gear wheel is threaded (3 threads) and the wire is rolled 1.5 times
    • In the middle wrap the wire enters an inclined hole and get retained using a jam screw
    • The wire returns to the thread using a second  inclined hole 
    • The ratio of diameters of  motor-roller and large gear wheel controls the transmission gear
    • For efficiency the large gear wheel is set closer to the driven link
    • Self-lubricated deep groove ball bearings are used for rotating elements
    • Light aluminum alloy is used
    • All unnecessary material is removed to reduce weight and inertia
  • Transmission loop (Gear wheel to linkage):
    • Unchanged

     

• Testing
  • Mechanism is tested in lifting a payload of 3-10 Kgs at different speeds without slippage
  • Excellent backdrivability at both ends for a moderate gear ratios
  • Ability to smoothly actuating the chain with low effort at both ends

               TASK 3: DESIGNING THE MAN-MACHINE INTERFACE OF MASTER ARM

• Research direction
  • Objectives
    • An effective man-machine interface between operator and master arm
    • An effective motion mapping  from operator hand to remote slave arm tool
    • Operator hand must be at the center of concurrency of last three DOFs
   
  • How to design the last 3 DOF of a  master arm so that the user can easily map his hand motion to a remote tool
    • Operator wearing a head-mounted display cannot see his hand nor the master arm he is holding
    • Operator needs a man-machine interface to logically maps his hand motion to slave arm tool
    • Operator thinks he is holding the tool through the master-slave system
    • A solution that failed (experiment-1)
      • Last 3 DOFs have concurrent rotation axes,
      • But operator hand center  is not the center of rotational concurrency
    • The operator hand center must be placed at the point of concurrency of last 3 DOFs
    • Operator hand center is also the origin of hand frame of reference

     

• Study of a passive master arm (experimment-2)
  • Operator hand is placed at the center of rotational concurrency of last 3 DOFs
  • decoupling operator hand position from orientation
  •  Minimizing number of iterations to set up the arm in a given configuration
  • Improved mapping between operator hand position and orientation and slave arm tool 

      TASK 4: DESIGNING LIGHT AND BACKDRIVABLE ROBOT ARMS FOR TELEROBOTICS

• Objectives

• The aim is a Telerobotic System that allows an operator carrying out remote work through a computer network
• To design a light, backdrivable master and slave robot arm while engineering the cost/performance ratio
• To develop an effective real-time client (master arm) and  server (slave arm) software system 
• To provide real-time stereo vision from the slave station to master station with head-mounted display
• A wire-based transmission is adopted to transmit motor power to gear wheel 
• Multiple loop transmission using steel wire from motor to linkage 

• Common features to both Master and Slave Arms ():
  • A 6 DOF, serial, anthropomorphic slave arm
  • Wire-based transmission to lower friction and cost
  • Motor-to-link chain has a gear loop followed by a number of transmission loops (see above)
  • Improved backdrivability, each motor-to-link chain can be easily actuated at both ends
  • Multiple independent transmission loops to make it fault-localized 
  • Designed to ease accessibility and maintenance   
  • Light material and robust structure, mobile arm linkage weight only 3Kgs
  • Last 2 DOFs have concurrent rotational axes to simplify arm kinematics
  • All six motors are grounded, all wire transmission go to ground through link 1 (see demo)

• Features of the Slave Arm
  • Last 2 DOFs controls a hub-gear (differential) motion of the gripper
  • Simple kinematics

   

• Features of the Master Arm
  • Operator hand is placed at the center of rotational concurrency of last 3 DOFs
  • decoupling operator hand position from orientation
  •  Minimizing number of iterations to set up the arm in a given configuration
  • Improved mapping between operator hand position and orientation and slave arm tool 
  • Last 3 DOFs controls a hub-gear (differential) motion of the gripper

   

• Testing
  • Tested in Bilateral Master-Slave mode in 2004 at the Robotics Lab and a US patent is pending for the master arm.

      TASK 5: A LIGHT (3 KGS), ANTHROPOMORPHIC BILATERAL MASTER-SLAVE TELEROBOTIC SYSTEM

             FROM WIRING, CONTROL ELECTRONICS, TO OPERABILITY

Development of the bilateral telerobot

• Wiring of master and slave arms (master-mechanics) and slave arm (slave)
  • Maintainable structure based multiple-loops
  • Accessible wring through new wheel structure
  • Revolutionary wiring attachment and installation
  • Tightly tensioned wiring to avoid undesirable elesticity

• Master arm mobility features (wired master) (Master-mobility)
  • Real anthropomorphic structure as it does not constrain human arm motion in any translation or orientation
  • Low impedance as whole arm weight 3 kgs,  low friction due to wire structure and fine mechanics 
  • Low gear (wire-based) linkage from grounded motors to joint and operator handle

   

• Designing and implementing arm control and power drive system (master-electronics)

Operability of master-slave bilateral system at the joint level and sight of slave scene

• Motion mapping in joint space (master-slave-xyz)
• Direct joint mapping (master-slave-xz)
• large motion bandwidth with a maximum speed of 5-10 mps (master-slave-xyz-cup)
• Ease of cognitive motion mapping in pouring operation (master-pouring)
• Insertion of a peg-in-hole with low clearance (0.02 mm) master-vision-insert

          3D stereo vision in master-slave bilateral system at the joint level 

• Operator holding master arm and wearing Head-Mounted-Display HMD (operator)

• Operator does not sees has arm but the slave arm tip and object through the HMD
• Operator is logically holding the remote object and moving his arm to properly move remote object

• Pouring task (master-vision-pouring1, master-vision-pouring2)

• Peg-in-hole insertion (master-vision-insert) and extraction (master-vision-extract)

            Potential development

• Design of an advanced computer aided teleoperation (CAT) to support pervasive quality remote work
• Develop a pervasive client-server software with real-time streaming of force and video information
• Experience the above Bilateral telerobot with its CAT on hard manual and automatic tasks
• Evaluate different working scales and faster networks (1Gbps Ethernet) in preparation for Internet 2 technology.

      POTENTIAL RESEARCH DIRECTIONS:

Develop a KFUPM research product in the area of telerobotics to support KSA needs

• Designing anthropomorphic master arms for robotic surgery, tight-safety and fire fitting, under water, and military.
• Designing of an advanced pervasive network connectivity to enable high-quality remote work using telerobotics
• Designing of stand alone, networked,  light, slave arm with force feedback with embedded computer and software
• Design of an Educational Telerobotic system (arm and Experiments) to equip graduate laboratory in Robotics, Mechantronics, Sensor-Based Computer Systems, Context-Aware Mobile Computers, etc.    
• Develop Software for real-time remote control and QOS through a computer network
• Develop a pervasive, fast, and accurate Stereo-Vision system that relays stereo frames through the Internet with Augmented Reality capability to augment a telerobotic system.

LONG TERM PLANS

• Transfer telerobotic design methodology and techniques
• Provide necessary training and consulting whenever needed
• Develop local skills to master the above technology whenever needed
• Help develop new telerobotic product tailored to specific applications whenever needed

Contact:  Professor Mayez Al-Mouhamed, Computer Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, KSA. Phone: 966-3-860-2934, Fax 966-3-860-3059, email: mayez@ccse.kfupm.edu.sa

              

        Please see the following papers for more details:

• Mayez Al-Mouhamed, Onur Toker, and Abdul-Khalik Al-Harthy, “A 3D Vision-Based Man-Machine Interface For Hand-Controlled Telerobot”, IEEE Transactions on Industrial Electronics,  Vol 52, No 1, 2005, pp. 306-319.

• Mayez A. Al-Mouhamed, Mohammad Nazeeruddin, and Syed M.S. Islam, Experimentation of a Multi-Threaded Distributed Telerobotic Framework, Under review with the IEEE Trans. on Instrumentation and Measurements, January, 2008.

• Mayez A. Al-Mouhamed, Onur Toker, and Asif Iqbal, A Multi-Threaded Distributed Telerobotic Framework, IEEE T.on Mechatronics, Vol 11, No 5, Oct., 2006. pp. 558-566.

• Mayez A. Al-Mouhamed, Mohammad Nazeeruddin, and Nesar Merah,  Design and Analysis of Force Feedback in Telerobotics, IEEE T. on Instrumentation and Measurements, Vol 58, No 6, 2009, pp.1949-1957.  

• Mayez A. Al-Mouhamed, Onur Toker, and Asif Iqbal, Experimental Evaluation of Feedback Modalities for Five Teleoperation Tasks, Accepted for publication, The IEEE Trans. on Instrumentation and Measurements, Accepted for future publication, Volume PP,  Forthcoming,  2009 Page(s):1 – 1, Digital Object Identifier 10.1109/TIM.2009.2023828.

• Mayez A. Al-Mouhamed, Mohammad Nazeeruddin, and Syed M.S. Islam, Performance Evaluation of a Multi-Threaded Distributed Telerobotic Framework, Under review with the IEEE Trans. on Instrumentation and Measurements, January, 2008.

• Mayez Al-Mouhamed, Onur Toker, Asif Iqbal, and M. Nazeeruddin, A Distributed Framework for Relaying Stereo Vision for Telerobotics, IEEE Inter. Conference on Pervasive Services, Beirut, Lebanon, July 19-23, 2004, pp. 221-225.
• M. Al-Mouhamed, M. Nazeeruddin, and A. Iqbal, A Modular Distributed Telerobotic Client-Server System, Inter. Conference on Information and Computer Science (ICICS’04), KFUPM, Dhahran, KSA, Nov, 28-30, 2004,
• Mayez A. Al-Mouhamed, Onur Toker, Asif Iqbal, and Syed M.S. Islam, Evaluation of Real-Time Delays for Networked Telerobotics, 3^rd Inter. IEEE Conference on Industrial Informatics (INDIN’05), 10-12 August 2005, Perth, Western Australia, pp. 351-356.
• Mayez A. Al-Mouhamed, Mohammad Nazeeruddin, and Syed M.S. Islam, Evaluation of Assembly Tasks in Augmented Telerobotics, 2nd International AUS Symposium on Mechatronics (AUS-ISM05), April 19-21, 2005, Sharjah, UAE.
• Al-Mouhamed, M., Buhari, S.M., Nazeeruddin, M., Islam, S.M.S., “Qualitative Evaluation of Computer-Aided Teleopearation”, In Proc. of the 4th ACS/IEEE International Conference on Computer Systems and Applications (AICCSA-06), March 8-11, 2006, Dubai,Sharjah, UAE.
• M. A. Al-Mouhamed, M. Nazeeruddin, and N. Merah, Design and Analysis of Force Feedback in Telerobotics, 3rd International AUS Symposium on Mechatronics, April 18-20, 2006, Sharjah, UAE.
• Syed M.S. Islam, M. Al-Mouhamed, S.M. Buhari, and Talal Al-Kharoubi, “A Hierarchical Design Scheme for Application of Augmented Reality in a Telerobotic Stereo-Vision System”, the Saudi 18^th National Computer Conference (NCC18), March 26-29, 2006. Riyadh, KSA.
• Islam, Syed M.S., Al-Mouhamed, M.A., Al-Kharobi, T. and Buhari, S.M. “Augmentation of a Telerobotic Stereo-Vision System Using Graphical Overlays,” Proc. of the First International Conference on Industrial and Information Systems (IIS), Peradeniya, Sri Lanka, August 8-11, 2006. (accepted for oral presentation).
• M. A. Al-Mouhamed, M. Nazeeruddin, and N. Merah, Force-Based Compliant Behaviors to Augment Telerobotics, 4th International AUS Symposium on Mechatronics, March 26-29, 2007, Sharjah, UAE.
• M. Al-Mouhamed and U. F. Siddiqi, Performance Evaluation of Auctions WLAN for RoboCup Multi-Robot Cooperation, The 7th ACS/IEEE International Conference on Computer Systems and Applications (AICCSA-2009), 10-13 May 2009, Page(s):610 – 615.

• Mayez Al-Mouhamed, A Closed Loop Control Architecture for Automatic Compensation of Variations in the Load. Registered at the CEA European Patent Office, Number 83400154.7, Designated States/Priority: BE/02, CH/07, LI/07, DE/01, GB/03, It/04, NL/04, and SE/06. January,1983.
• Mayez Al-Mouhamed, M. Csakvary, B. DeCosnac, and J.P. NoelA, Robotics Mechanism for Measuring Force Constraints By using Few Degrees of Freedom between its Base and its Contact Platform, Registered at the CEA European Patent Office, Number 83400153.9, Designated States and Priority as above. (with M. Csakvary, B. DeCosnac, and J.P. Noel), January,1983
• Mayez Al-Mouhamed, Hybrid Analog Control Structure, United States Patent  4549261, October, 22, 1985.
• Al, Mouhamed Mayez, Csakvary, Etienne,  De, Cosnac Bertrand, Noel, Jean-paul, Measured-force gripper device of articulated structure having several degrees of freedom, United States Patent 5080415,  1986.
• Mayez Al-Mouhamed and Nesar Merah, “Anthropomorphic Force Reflecting Master Arm for Telerobotics”,  Pending US Patent, Assignment Document Docket No. 18692.57 (CSE0085), Serial No 12289792, March, 2009.