Changes between Initial Version and Version 1 of WAM/SystemComponentList

May 12, 2011, 7:50:29 PM (11 years ago)



  • WAM/SystemComponentList

    v1 v1  
     1= WAM component list =
     3The standard four-degree-of-freedom WAM Arm, shown in Figure 1, has four cable-driven joints labeled J1 through J4, and four brushless DC motors labeled M1 through M4. M1 controls the yaw (J1) of the WAM and is located in the base of the WAM.  Using Barrett’s patented cable differential, M2 and M3 together control the pitch (J2) and roll (J3) of the WAM, and are contained in the shoulder of the WAM. M4 controls the bend of the “elbow” (J4), and is located just above M2 in the shoulder. Using Barrett’s Puck technology, all motor encoders, power amplifiers, and controllers are located in a single compact package adjacent to each motor, eliminating the need for a controller cabinet and heavy electrical cables.
     6#!div class="center" align="center"
     9'''Figure 1: WAM Arm'''
     12The standard WAM Arm comes with an internal computer and a blank outer link (shown attached to the end of the elbow in Figure 1 and shown in full in Figure 2). However, several options (see Section 1.2) such as an external computer and the WAM Wrist (Figure 11) are available to replace these (though both standard options will still be included so that you may always switch between configurations at any time).
     15#!div class="center" align="center"
     18'''Figure 2: Blank Outer Link'''
     21The WAM’s internal computer has the following specifications:
     22Mainboard: PFM-540I
     23Processor Type: AMD Geode LX800 x86 @ ~500MHz
     24Memory: 256MB (4MB of that is used as a video framebuffer).
     25Hard drive: 2GB, !CompactFlash
     26Kernel: Linux patched with Xenomai 2.4-rc5
     27Distro: Slax 5.1.8
     28Expansion Card: PEAK-System PC/104 CAN Card, 2 ports
     29Wireless: Wi-Fi 802.11 b/g
     30Ethernet: 10/100 Base-T
     32=== Tool-End Attachments ===
     33The WAM™ comes with three endpoint (tool-end) attachments that can be used to change the setup and shape of the WAM™ Arm: the Haptic Ball, the Tool Plate, and the CAN Termination. These items in general will be attached to either the Outer Link (Figure 2) or WAM Wrist (Figure 11). Figure 3 shows the end plates of both the Wrist and Outer Link. The wires and connector coming out of the centers are for running the optional Barrett Hand. If using the Outer Link without the Barrett Hand, the wiring can simply be pushed inside the large open cavity. If using the Wrist without the Barrett Hand, the wires should be coiled neatly in the small cavity and the Wrist Plug installed to keep the wires from getting pinched.
     36#!div class="center" align="center"
     39'''Figure 3: End Plates of Wrist and Outer Link'''
     42The Haptic Ball (see Figure 4) can be attached to the end of the Outer Link or the Wrist. It is used to assist in haptic scenes by providing an easy-to-grasp, definable endpoint for the user. Systems are generally shipped with the Haptic Ball pre-installed.
     44The Tool Plate (see Figure 5) can be installed on the end of the Outer Link, Wrist, or Elbow Plate (if neither the Outer Link nor Wrist modules are installed). It provides a flat base that can be used to attach parts other than the ones designed by Barrett.  The Tool Plate has four M6 tapped holes, evenly distributed in a circle, a 6-mm diameter dowel-pin hole, a quick-connect pin hole and slot, and two holes to connect the CAN Termination (see 9.2.3 for Tool Plate hole labels and dimensions).
     46The CAN Termination (see Figure 6) must be used if neither the Outer Link nor the Wrist is attached at the end of the elbow.  The CANbus must be terminated at each end with a 120 Ohm resistor to minimize signal reflections. The termination can be attached to either the end plate of the elbow or to the Tool Plate (if attached to the elbow) by the two small holes, which are the same distance apart as the holes on the Termination.
     49#!div class="center" align="center"
     52'''Figure 4: Haptic Ball'''
     56'''Figure 5: Tool Plate'''
     60'''Figure 6: CAN Termination'''
     63=== Power Supply ===
     64The WAM system generally requires an input voltage of 48 VDC. However, if you require an alternate input voltage, contact Barrett Technology. The power requirements for both 4-DOF and 7-DOF WAMs are summarized in Section 3.6.1. Any DC power sources may be connected directly to the WAM.  Improper grounding can cause severe damage to the WAM electronics.  If you are concerned that your voltage source may damage the WAM electronics, do not hesitate to contact Barrett for technical guidance.
     66The Power Supply that ships with the WAM, shown in Figure 7, can be plugged into any regular AC power source. It provides up to 10A of direct current at 48V. This Power Supply switches automatically to local voltage standards (100-120 & 200-240 VAC at 50-60Hz) around the globe and contains built-in surge protection.
     69#!div class="center" align="center"
     72'''Figure 7: Power Supply'''
     75=== Safety Pendants ===
     76The WAM Arm system comes with two safety pendants: a control pendant and a display pendant (shown in Figure 8). Both pendants show the present safety status of the WAM Arm, with status lights for the velocity, torque, voltage, and heartbeats of the robot. There is also a 7-segment LED single-character display which shows additional information related to any existing errors. Each pendant has a large mushroom-type emergency stop button, which can be reset (popped up) by rotating the button clockwise for one quarter of a full turn. The control pendant has three additional buttons: Shift, Reset/Idle, and Activate.
     79#!div class="center" align="center"
     82'''Figure 8: Safety Pendants'''
     85=== Electrical Cables ===
     86All necessary electrical cables are included with the basic WAM System, shown in Figure 9. An AC Line Cord connects the Power Supply to a wall source. A blue DC Power Cable connects the Power Supply or another DC power source to the WAM. If you purchased an external WAM PC, a purple CANbus cable is provided for CAN communication with the WAM. The pendant cables (shown attached to the pendants in Figure 8) connect directly to the WAM. An Ethernet cable is also provided for the option of Ethernet communication with the WAM.
     89#!div class="center" align="center"
     92'''Figure 9: Electrical Cables '''
     95== Control Software and Firmware ==
     96The WAM’s internal computer has firmware and software that are preloaded before it is shipped.
     98Included with a copy of the source code in electronic form are:
     99        1. User’s Manual (this manual)
     100        1. Quick Start Guide
     101        1. Cable Maintenance Guide
     102        1. Inertial Specifications Manual
     103        1. Support Resources Reference Sheet
     105For more information about software and firmware, please see Section 4.
     108== Maintenance Kit ==
     109Included in each WAM package is a maintenance kit (shown in Figure 10). Use the maintenance kit in accordance with the instructions in Section 3 and the Cable Maintenance Guide. The maintenance kit includes the following:
     111        * 1 Tool Plate (normally shipped attached to the Outer Link (or Wrist if purchased))
     112        * 4 M10 Screws, Washers, and Nuts to secure the base
     113        * 1 Set of Metric Hex Wrenches
     114        * 1 Packet of Loctite 222
     115        * 1 10-mm Combination Wrench
     116        * 1 Pair of Tweezers
     117        * 2 Clamps (for clamping the WAM to a table top)
     118        * 1 Roll of 13-mm (1/2”) Masking Tape
     119        * 1 Roll of Kapton Tape
     120        * 1 Slotted Screwdriver
     121        * 1 Phillips-Head Screwdriver
     122        * 1 Push-Pull Hook
     123        * 1 Set Spare Mechanical Cables (Packaged separately from the rest of the Maintenance Kit)
     126#!div class="center" align="center"
     129'''Figure 10: Maintenance Kit'''
     132== System Options ==
     134=== WAM Wrist ===
     135The WAM Wrist module, shown in Figure 11, replaces the outer link of a four-degree-of-freedom WAM, adding joints 5, 6, and 7, for another three degrees of freedom. Mechanical and electrical quick-connect features make it easy to swap between the WAM’s outer link and the Wrist module to convert between 4-DOF and 7-DOF configurations.
     137In order to minimize the inertial effects of the motors on the host robot arm, the servomotors for joints 5 & 6 are located at the base of the wrist. The final roll joint in the WAM Wrist, motor joint 7, is the only geared axis. At very small scales, such as at joint 7, gears have slightly better performance than cables in terms of compactness.
     140#!div class="center" align="center"
     143'''Figure 11: WAM Wrist'''
     146The WAM Wrist comes with its own separate maintenance kit (shown in Figure 12), which contains:
     147        * 1 Roll 6-mm (¼") wide Masking Tape
     148        * 1 Wrist Tension Tool
     149        * 1 Joint-7 Spanner Tool
     150        * 1 Pull Hook
     151        * 1 Wrist Safety Termination (Packaged separately from the rest of the Maintenance Kit)
     154#!div class="center" align="center"
     157'''Figure 12: Wrist Maintenance Kit'''
     161=== Passive Gimbals ===
     162The passive gimbals option, shown in Figure 13, replaces the Outer Link on the WAM and adds three additional unpowered degrees of freedom. The links of the gimbals are designed to provide a large mounting area at the intersection point between all three joint axes. A vertical bar grip comes standard and is designed primarily for life-size haptics, exercise, and rehabilitation; but other grip and mounting options are available. The gimbals use Barrett Technology’s quick-connect system so that it may easily be interchanged with other end effectors.
     164A 6-axis force/torque (FT) sensor can be mounted at the base of the gimbals grip for gathering additional data. This sensor is redundant with the built-in Cartesian Force/Torque control capabilities of the WAM, but enables a separate confirmation of values at slightly higher precision.
     167#!div class="center" align="center"
     170'''Figure 13: Gimbals Option'''
     173=== External WAM PC ===
     174Barrett Technology offers an external PC (see Figure 14) for advanced control applications that require more processing power or more memory than the WAM’s internal PC can provide. A standard keyboard and mouse, CANbus cable, and 2-m AC line cord are provided for use with the external PC. A monitor (not provided) is needed only during the initial setup of the computer. The external PC has the following specifications:
     176Mainboard: Intel 945G Micro ATX
     177Processor Type: Intel Core 2 Duo E6600 Conroe @ ~2.4GHz
     178Memory: 2GB (4MB of that is used as a video framebuffer).
     179Hard drive: 80GB
     180Optical: DVD Drive
     181Kernel: Linux patched with Xenomai
     182Distro: Ubuntu 7.10
     183Expansion Card: PEAK-System PCI ISO dual-port CAN card
     184Ethernet: 10/100/1000 Base-T
     187#!div class="center" align="center"
     190'''Figure 14: External WAM PC'''
     194'''Figure 15: Back of External WAM PC'''