🚀 go-pugleaf

In article <848@engcon.marshall.ltv.com>, simon@engcon.marshall.ltv.com (SHSIMON) writes...
> 
>To WIllie Smith
> 
>Could you post more information about WALDO ?
> 
>Does it currently exist ?   Does it work out of the line of sight? etc.
> 
>Thanx,
>Hank

OK, I've probably gotten enough requests for my teleop documentation that 
it's worth posting it.  The vehicle does exist, at least we've got a 
chassis that moves under conputer control (very very crude right now).  In 
fact, I expect to be testing the RC-232 radio link tonite at 1200 baud, 
stay tuned for results.  It doesn't work out of sight yet, but once I get 
my ham radio license (Technician class no longer requires morse code!), I 
expect to start gathering hardware together for TV links and command/
telemetry links with up to a one-mile range.

Willie

-------------------------------------------------------------------------
[This condensed version of TELEOP.DOC was generated 01/01/91 WPNS]

 Sunswick Engineering Teleoperations

   1 Overview

      Sunswick Engineering (that's me, Willie Smith, with my OEM 
      hat on, with lots of assistance from others) has been doing
      teleoperations research since 1987, focusing on modelling  
      vehicles that might be used in support of a lunar colony.  
      Tycho, the first generation machine, has been complete     
      since mid-1988, and Waldo, the next generation machine, is 
      currently in the assembly phase.  The Tycho project was    
      done in part for the semi-mythical Lunar Society, a        
      volunteer organization promoting manned space exploration  
      and colonization.                                          

   2 What is teleoperation?
      Teleoperation is basically remote control of a device from 
      a separate (usually distant) location.  Lunar teleoperation
      is the remote operation of a vehicle which is on the       
      surface of the moon while the operator is on the earth.    

      The general case of a lunar teleoperated vehicle is one    
      which can be moved by radio controls (telecommand) and     
      which sends real-time pictures (and other telemetry) back  
      to the operator by means of a video camera.  It has other  
      features (such as a bulldozer blade, a manipulator arm,    
      etc) that allow it to do useful work in support of a lunar 
      colony.                                                    

   5 Tycho

      5.1 General
         The first generation vehicle was built using            
         radio-control hobbyist equipment originally intended for
         use in R/C planes and cars.  It is named Tycho after the
         prominent crater on the moon of that name, which in turn
         is named after the noted astronomer Tycho Brahe.        

      5.2 Hardware
         The basic vehicle is a highly modified Tamiya(?)        
         Clod-Buster (TM) four wheel drive car-crushing pickup   
         truck (model) chassis with a Futaba 7-channel radio     
         control.  A Sony Watchcam camera and a channel 14 UHF TV
         transmitter get a TV image back to the operator.  An    
         S-100 machine with a 7 MHz Z-80 running CP/M and a      
         Commodore Amiga with genlock make up the computer gear. 

      5.3 Software
         Code written in Z-80 assembly reads the operator's      
         controls, generates the 3-second delay, logs control    
         positions, and drives a modified R/C transmitter.  Amiga
         BASIC code provides a Heads-Up-Display to give the      
         operator easily- assimilated information on control     
         positions.  The two machines communicate through an     
         RS-232 link using a predefined protocol.                

      5.4 Goals
         The major goals of the Tycho project were to prove that 
         teleoperated vehicles could be modelled 'on the cheap'  
         and to build such a device.  We planned to do some      
         examples of useful work that would show a proof of      
         concept that lunar teleoperations can be done, that they
         would be useful, and that operators could be trained to 
         control vehicles with a 3-second delay.  We also planned
         to gather data on a number of different operators with a
         number of different control schemes and massage the data
         to determine empirical answers to the questions: "What  
         is a good way to set up the controls?" and "What makes a
         good operator?"                                         

      5.5 Sucesses
         We proved that modelling lunar teleoperations is        
         possible by building the model, and we convinced        
         ourselves that operators could indeed learn to cope with
         the 3-second delays.  As a proof of concept, Tycho is a 
         success.  We also managed to build the project without a
         'NASA' budget.                                          

      5.6 Failures


                                                                          3
         We didn't actually do any 'useful' work with Tycho, as  
         the mechanical parts are too flimsy and the vehicle is  
         too small to attach (say) a bulldozer blade and try to  
         push some sand around.  We also failed to answer the    
         "goodness" questions above, due to lack of time and     
         inconsistant data from a vehicle that's difficult to    
         control.                                                

      5.7 Costs
         The total costs of the Tycho project were around $3,000.
         This does not include donated equipment, computer      
         equipment we had on hand, or anyone's time.  It was     
         arrived at by adding up all the costs of the things that
         we wouldn't have bought if we weren't doing the project.


   6 Waldo

      6.1 General
         The second generation vehicle is being built using the  
         lessons we learned while building Tycho.  Most of them  
         revolve around the theory that "Bigger is better", and  
         "Keep It Simple, Stupid."  The name was chosen because  
         it more closely defines the project - a waldo is a      
         remote manipulator used for handling objects at a       
         distance.                                               

      6.2 Design goals
         The major problems with Tycho had to do with the small  
         size.  Waldo is going to be as large as possible,       
         consistent with moving it through doorways and          
         transporting it in a car.  Steering control with Tycho  
         was difficult at best, so the problems of steering and  
         suspension will be eliminated at the source. There will 
         be four (lawn-tractor sized) wheels with independent    
         drive motors, and steering will be done by driving the  
         wheels on either side at different speeds.  An on-board 
         computer (or two) will run the drive motors and other   
         accessories, and will communicate with the base computer
         via a packet radio link.  Dual ATV (Amateur TV)         
         transmitters will send separate or stereo TV images back
         to the operator(s).  A bulldozer blade will allow       
         earthmoving experiments, and a manipulator arm will be  
         used for more precise work.  Other accessories will be  
         added as time (and money) allow.  The original goals of 
         determining operator and control "goodness" remain in   
         effect.  Operating time must be at least an hour between
         recharges, and recharge should take no more than an     
         hour.                                                   

      6.3 Design non-goals
         We are not building something that will be expected to  
         go to the moon, so we don't need to worry about vacuum, 
         temperature, lunar soil composition, or gravitational   
         effects.  We are not building an all-terrain vehicle,   


                                                                          4
         nor one that can operate more than 1/2 mile from the    
         base.  While we will attempt to make the base easily    
         portable, it is possible that moving the base will      
         require a small van and a day or so of packing/unpacking
         and setting up the control computers.  While these are  
         interesting topics of conversation, they aren't problems
         that need to be considered for Waldo.                   

      6.4 Timetable
         Since we are doing this in our spare time and with a    
         limited budget, there is no deadline or timetable.      
         Tycho took about a year to get to the point where the   
         hardware was reasonably stable, and we expect that the  
         Waldo project may take 2-3 years to get to the same     
         point.  We would like to have a moving platform by the  
         end of 1990, however, so that we can start using the    
         basic vehicle while adding on features.                 

         Benchmark:  Dec 11, 1990                                
         The frame has been built, the platform, wheels, and     
         motors have been fitted for the last time (lock-tight on
         all relevant fasteners), the motor source wiring has    
         been completed, and the FET power-drivers are halfway to
         completion.  The vehicle should be moving under control 
         of the on-board computer by mid January.                

      6.6.B Pending work.

         A partial list of subsystems that need work:            

         Cameras - stereo configurations, mounting and pointing  
         Bulldozer blade - mechanical design and fabrication,    
         electrical drive                                        
         Radio gear - selection, operation, antennas, duplexers, 
         packet, ATV                                             
         Audio delay to simulate onsite workers                  


                                                                          5
         Operator's console - controls, telemetry displays       
         Postprocessing - operator and control "goodness"        
         Manipulator arm - programming, operator and computer    
         interfaces                                              
         Flux-Gate compass - computer interface and autopilot    
         programming                                             
         Sonar - rangefinding, "LORAN" positioning, collision    
         avoidance                                               
         Laser - pointing, position finding                      
         Batteries - chargers and state of charge determination  
         Base computers - hardware interfaces, lots and lots of  
         software(!)                                             
         Operating personnel - see 6.7.3.5                       
         Test pilots (once the vehicle is drivable)              
         Documentation - written, photographic, schematic, CAD.  

      6.7 Current design concepts

         6.7.1 General
            The following are our current ideas of how Waldo is  
            going to be configured.  They are subject to change  
            at any moment.  The two major parts of the project   
            are the vehicle and the base station.                

         6.7.2 Vehicle

            6.7.2.1 General
               The main constraints on the vehicle are that it be
               light in weight (two-person carry is our goal), be
               able to fit through doorways, and be transportable
               in a VW Golf.  With those constraints in mind, it 
               should be as large and sturdy as possible.        

               The vehicle is a flat platform with four fixed    
               wheels. Differential steering will be used (like a
               Bobcat), and suspension problems have been        
               eliminated at the source (there is no suspension, 
               the wheels are fixed to the chassis).             



                                                                          6
               The main height constraint is that the vehicle can
               be carried through doorways sideways.  This means 
               that the vehicle must be less than 2 feet high,   
               not counting removable subsystems like antennas.  
               The width constraint is the size of the hatchback 
               and trunk on a VW Golf - 39 inches.  In order to  
               steer easily, the vehicle should have an          
               approximately square aspect ratio.  The base is   
               29.5 inches long without plow blade.  Weight      
               should be kept below 100 pounds to allow          
               two-person carry.  Removable subsystems           
               (manipulator arm, batteries, plow blade, etc) will
               allow us to keep the carry weight down while      
               allowing the assembled weight to exceed the 100   
               pound limit.  Total assembled weight should still 
               be under 200 pounds.                              

            6.7.2.2 Chassis
               The frame is made of 1.25-inch square aluminum "U"
               channel bolted together. Solid aluminum blocks are
               used at the corners to provide strength and       
               prevent the channels from collapsing.  The frame  
               is 29.5 inches long and 25 inches wide, with a    
               single stiffener in the middle between the wheels.
                Additional                                       
               solid blocks are fastened to the bottom of the    
               channels to provide mounting points for the       
               shoulder bolts which function as stub axles.  The 
               wheels bring the total width to 36.5 inches.      

            6.7.2.3 Drive
               The wheels are Wheelhorse garden tractor front    
               wheels with 13x5.00-6 tires, and are chain-driven 
               from modified Makita and Sears cordless drills.   
               The vehicle moves about 3 feet per second, or 2   
               miles per hour.  More speed is not desirable, as  
               it leads to less precise control over the vehicle.
                Worst case, Waldo may move as much as 9 feet     
               before the operator can react!                    

            6.7.2.4 Computer
               There will be at least two onboard computers, one 
               for the drive subsystem and one to control the    
               rest of the vehicle.  The drive subsystem is run  
               by a Micromint RTC-52 single-board computer with  
               assembly language routines to control PWM motor   
               drivers.  While this computer has an onboard BASIC
               interpreter, we found that it couldn't generate   
               the four PWM outputs fast enough.                 

               The main onboard computer has not yet been        
               selected, but will probably be a Micromint        
               RTC-180, a 64180-based single-board computer.  It 
               will control the radios, robot arm, autopilot,    
               plow blade, and other systems.  It will be        


                                                                          7
               programmed in Z-80 (or 64180) assembly.           

            6.7.2.5 Radio
               The radio gear will operate on the amateur bands, 
               and comprise packet radio command and telemetry   
               links as well as two channels of ATV video        
               feedback for the operator.  The video channels    
               will be switched between various cameras and other
               on-board video sources (computer terminal, etc).  
               Exact frequencies and configuration of the radio  
               gear have not yet been chosen.                    

            6.7.2.6 Cameras
               The current plan for cameras is to have a         
               full-color CCD camera on a pan/tilt mount with    
               power zoom lens for the main operator to use while
               driving the vehicle.  This will be supplemented by
               a stereo pair of tube-type Sony Watchcam cameras  
               for use with the manipulator arm.  There will also
               be 'overview' cameras positioned around the       
               worksite.                                         

            6.7.2.7 Manipulator arm
               A Heathkit HERO-2000 robot arm modified for       
               battery operation will be mounted on the back of  
               the vehicle facing aft.  Assembly of the arm was  
               completed during the beginning of July, 1990.  The
               arm will be used for fine-control experiments.  As
               a 'graduation exercise', a teleoperator in        
               training may have to stack glassware with a       
               three-second delay!                               

            6.7.2.8 Power
               Power will be provided by Gates Cyclon lead-acid  
               batteries.  Voltage regulators and/or converters  
               will provide a number of common voltages (+5, +12,
               -12, etc) for onboard systems.  Separate batteries
               will be used for drive, computer, arm, and radio  
               gear to prevent interactions.  If power to the    
               computers or radio gear fails or drops below      
               certain minimums, all power to the vehicle will be
               disabled to prevent uncontrolled movement.        

               The drive battery is four 'BC' cells in series,   
               giving 25 amp-hours at 8 volts to drive the four  
               motors.  Since the cordless drills the motors are 
               based on run on 7.6-volt NiCad batteries, this is 
               probably a good compromise.  Since the Cyclon     
               cells have a much higher current capacity than the
               original NiCads, the drive computer will have to  
               monitor currents and limit drive if a wheel       
               stalls.                                           

            6.7.2.9 Bulldozer blade
               There will be a blade on the front of Waldo that  


                                                                          8
               will allow the operator to model some construction
               work, like leveling a landing field, excavating a 
               habitat module foundation, covering a habitat, and
               so on.  Digging in the sand at a beach will be a  
               good test of these skills.                        

         6.7.3 Base station

            6.7.3.1 General
               The base station is where the operator sits,      
               controls the vehicle, and views the telemetry.    
               The other support personnel also sit here.  We    
               hope to be able to make the base reasonably       
               portable, so that we can (for instance) go to a   
               beach and dig in the sand or go to an SF          
               convention and recruit 'test-pilot' operators.  By
               monitoring the response of novice operators, we   
               can get a better idea of control 'goodness'.      


                                                                         12


For more information:
         Please contact Willie Smith at one of the addresses     
         below:                                                  

         Willie Smith                                            
         P.O. Box 2452                                           
         Acton, MA 01720                                         

         SNDPIT::SMITH   (on DEC ENET)                           

         smith@sndpit.enet.dec.com                               
         smith%sndpit.enet.dec.com@decwrl.dec.com                

         w_smith@bix