2021 Requirements

This document outlines the requirements for the rover to be able to perform well in the 2022 URC competition.

See rules for more details:

 

image2021-4-5_18-29-28.png

2021 Competition Missions

  1. Science Mission
    1. Teams need to be able to investigate multiple sites of mineralogical and biological interest within a 0.8 km radius of the start gate
    2. Using the on-board science package on the rover, teams must determine the absence or presence of life, either extinct or extant, for designated samples
    3. The rover may user cameras or other passive instruments to investigate the area, and may dig using mechanical methods
    4. The rover must have a life detection capability instrument of the team's choosing
    5. Samples must be investigated and analyZED on-site using equipment aboard the rover
    6. Soil may be removed from the sample site, but rock samples must not be removed or altered
    7. Any chemicals used on board, including water or reaction products, must follow a no spill policy and be contained within the rover
    8. After collecting samples and performing onboard analysis, teams must prepare a 10-15 minute presentation for the judges discussion conclusions for each site regarding the presence or absence of life, and whether or not life is extant or extinct. Presentation must also include the meaning of data collected with respect to the habitability potential, the geology of the site (past and present) and implications of the site being suitable for life.
    9. Teams will be given between 30 and 45 minutes to collect data on the rover
  2. Extreme Retrieval and Delivery Mission
    1. Traverse a wide variety of terrain, no further than 1 km from the start gate
    2. Terrain includes soft sandy areas, rough stony areas, rocks and boulder fields, vertical drops and steep slopes
    3. Might be out of direct line of sight for portions of the course
    4. The rover will be required to pick up small lightweight hand tools (screwdriver, hammer, wrench), supply containers (toolbox, gasoline can) or rocks up to 5 kg in mass. All items will have graspable features no greater than 5 cm in diameter except the rocks.
    5. The rover will be required to pull one object by a rope over relatively flat ground (rope is no thicker than 15 mm in diameter, no more than 3 m in length, and the object will be less than 5 kg)
    6. Objects shall be picked up in the field and delivered to designated locations, with approx. GPS coordinates given
    7. total time on course will be between 30 and 60 minutes
  3. Equipment Servicing Mission
    1. The rover shall travel up to 0.25 km across relatively flat terrain
    2. Pick up a cache container and transport to the lander rocket. Cache will have a handle of at least 10 cm long and not more than 5 cm in diameter. Cache will weigh less than 3 kg
    3. Open a drawer on the lander and insert cache into a close fitting space in the drawer and close the drawer
    4. Tighten captive screw to secure drawer. The screw will be a 5/16” Allen (hex) head. Teams may build the hex driver into the rover, or pick up the screwdriver provided.
    5. Teams may build the hex driver into the rover or pick up the screwdriver provided
    6. Undo a latch on a hinged panel of the lander and open the panel
    7. Type commands on a mechanical keyboard and follow directions on computer display
    8. Operate a joystick to direct an antenna while observing a gauge
    9. Pick up and insert a USB memory stick into a USB (type A) slot on the lander
    10. Push buttons, flip switches, turn knobs
    11. Teams will have between 20 and 45 minutes to complete the mission
  4. Autonomous Navigation Mission
    1. Rover will need to traverse autonomously between posts or between gates across moderately difficult terrain
    2. Cumulative distance of all legs shall be no greater than 2 km
    3. Total time on course will be between 30 and 45 minutes
    4. Each post will have a larger 20 cm x 20 cm marker, 30-100 cm off the ground. Each gate will consist of a pair of posts 2-3 m apart. Each marker will display a black and white AR tag (see  https://wiki.ros.org/ar_track_alvar?action=AttachFile&do=view&target=markers0to8.png)
    5. Legs will increase in difficulty:
    6. Stage 1: 
      1. Leg 1: GPS coordinates of the post provided
      2. Leg 2: GPS coordinates of the post provided
      3. Leg 3: GPS coordinates up to 5m from the post. Rovers will need to autonomously detect AR tag on the post and drive to it
      4. Leg 4: Autonomously drive through a gate with posts 3 m appart
    7. Stage 2:
      1. Leg 5: GPS coordinates up to 10m from gate. A small autonomous search pattern may be required to locate the gate if gate is not initially detected
      2. Leg 6: GPS coordinates between posts provided, autonomous obstacle avoidance required
      3. Leg 7: GPS coordinates up to 10m from gate. Obstacle avoidance and autonomous route finding required
    8. LED indicator required on the back of the rover, visible in bright daylight that will signal:
      1. Red - Autonomous operation
      2. Blue - Teleoperation (Manual driving)
      3. Flashing Green - Successful completion of leg
    9. The rover's on-board systems are required to decide when it has reached a post or passed through a gate. The rover must then stop and signal completion of a leg using the LED indicator on the back of the rover. It must also display a message or signal on the operator's display for the control station judge to observe
    10. Operators may send a signal to the rover to abort the current attempt and autonomously return to the previous post/gate or GPS coordinate and stop within 10 m of it. Teleoperation is allowed but the team forfeits 50% of its points to that leg. No points deducted for autonomous return.
    11. While stopped at any post/gate/coordinate, teams may program the next leg and make changes to the control, but may not drive the rover

Competition Requirements

General

  • Max budget is $18,000 USD (~$22,000 CAD). Includes components for the rover, rover modules, power sources, communications equipment, base station equipment and all command and control equipment. Does not apply to spare parts, tools and travel expenses.
  • Rover must be a stand-alone, off the grid mobile platform. Tethered communication and power are not allowed. The primary platform may deploy any number of smaller sub-platforms.
  • The rover must fit completely within a 1.2 m x 1.2 m box for weighing. It can fold to fit within the transport crate but may not be disassembled to do so.
  • No vertical height limit (might change for 2022)
  • Max deployable weight of the rover for any competition mission is 50 kg. The total mass for all fielded rover parts is 70 kg. Weight limit does not include any spares or tools used, but does include any items deployed by the rover such as sub-rovers, cameras and communication relays
  • Air breathing propulsion systems are not permitted (combustion, hydrogen, etc.)
  • For 2021, no airborne or lighter-than-air systems were allowed (might change for 2022)
  • Rovers must have a kill switch that is readily accessible on the exterior of the rover (stops the rover's movements and cease all power draw)
  • The team must be able to set up all necessary systems and be ready to compete in no more than 15 minutes
  • The team must be able to disassemble all equipment in no more than 10 minutes
  • Teams do not need to return to the start gate or collect any deployed items before the end of time for any of the missions
  • Rover must have a robotic arm capable of performing dexterous operations
  • Rovers shall be able to withstand these conditions and also light rain, but will not be expected to compete in heavy rain or thunderstorms.
  • Field science expertise may be useful for some tasks such as identifying a type of rock

Communications

  • The rover shall be operated remotely with wireless communications and no time delay (potentially out of line of sight)
  • Communications methods must adhere to all applicable FCC regulations 
  • Camera cannot be mounted on top of a base station antenna to obtain visual feedback
  • Base station antenna limited in height to 3m
  • Antenna bases much be located within 5 meters of the team's command station
  • Any ropes or wires used for stabilization must be anchored within 10 meters of the command station
  • All teams must bring at least 25 m of communications cables 
  • Teams shall not use frequency bandwidths greater than 8 MHz
  • Teams must be able to operate exclusively within the 3 following sub bands: 
    • 900-Low (902-910 MHz)
    • 900-Mid (911-919 MHz)
    • 900-High (920-928 MHz)
  • Teams shall use center frequencies that correspond to channels 1-11 of the IEEE 802.11 standard for 2.4 GHz
  • Teams shall not use frequency bandwidths greater than 22 MHz
  • Teams will not use more than three channels in the 2.4 GHz band
  • Teams are allowed to operate in bands outside of 900 MHz and 2.4 GHz


Table of Values - General

DescriptionValue
Maximum budget$18,000 USD
Rover dimensions1.2 m x 1.2 m in box
Rover mass (in a mission)50 kg
Rover mass (total)70 kg

Table of Values - Communications

DescriptionValue
Base station antenna height (maximum)3 m
Antennae distance from command station (maximum)5 m (but prepare for up to 25 m)
Base station stabilization equipment distance from command station (maximum)10 m
900 MHz maximum bandwidth8 MHz
2.4 GHz maximum bandwidth22 MHz
Separation between competition areas (minimum)

0.5 km

Time to prepare to compete after being given command station access15 min
Time to fully disassemble equipment at end of event10 min

Table of Values - Science

DescriptionValue
Mission distance from starting position (maximum)0.8 km
Mission time30-45 min
Science presentation time10-15 min


Table of Values - Retrieval and Delivery

DescriptionValue
Mission distance from starting position (maximum)

1 km

Mission time30-60 min
Maximum rock mass5 kg
Graspable handle diameter (maximum)5 cm
Retrievable object dimensions (maximum)40 cm x 40 cm x 40 cm
Rope diameter (maximum)15 mm
Rope length (maximum)3 m
Attached object mass (maximum)5 kg

Table of Values - Equipment Servicing

DescriptionValue
Mission distance from starting position (maximum)0.25 km
Mission time20-45 min
Cache container handle diameter (maximum)5 cm
Cache container handle length (minimum)10 cm
Cache container mass (maximum)3 kg
Allen key size5/16"

Table of Values - Autonomy

DescriptionValue
Cumulative mission distance between legs2 km
Mission time30-45 min
AR tag post dimensions20 cm x 20 cm
AR tag height from ground30-100 cm
Post distance at gates2-3 m


Table of Penalties

DescriptionPenalty
Late expense record (May 24, 2021)10% total points per day late
Failure to fit into weigh-in box (1.2m x 1.2m)40% of mission points
Overweight rover5% of mission points per kilogram overweight
Intervention20% of mission points per intervention
Teleoperation to a previous gate during Autonomous Navigation50% points for that leg

Last Year's Feedback

What Worked:

What Didn't Work:

  • Motor voltage consistency
  • 360 degree continuous rotation wrist

Short Term Goals (~2months)

  • WORKING ARM (TOP PRIORITY AFTER LOCKDOWN IS LIFTED)
  • FW/SW test fixtures for the arm
    • test joint fixture (motor controller hooked up to a motor)

Feature Wish List

(Place all of the desired features here in bullet point format)

  • Remote control of the rover over a short distance (using a controller directly connected to the rover without going through the antennas, similar to a rc car)
  • Rail gun
  • Easily deployable remote control station (like a briefcase which contains multiple screens and controllers to control the robot at a distance)
  • Competition Unit With a Portable Toolbox and Spare Parts
  • Deployable drone or mini rovers (if allowable by competition)
  • Mock up testing facilities (elements to be included tbd)
  • Joystick control of the robotic arm end-effector for maximum 3D control - 6-axis sensor like space mouse?
  • Refine mechanical arm precision high enough to utilize high precision absolute encoder sponsors
  • The ideal motor controller is an o-drive (for arm and drivetrain) with BLDC motors
  • In rush current measurements and capacity measurements for the battery
  • Custom gamepad controller
  • Carbon fiber
  • Underglow
  • Paint job
  • Status LEDs for power/board status
  • Fastener inventory
  • maybe a magnet on the arm(as a lot of the objects required to be picked up seem like metal)
  • what if we had a real life model of the arm at the control station and moved that around to attain exact control of the actual arm
  • (for autonomous mission), if not already being done, for autonomous return to the previous post could just trace back steps with recorded position data

Mechanical Requirements

(Place all of the requirements here in a bullet-point format)

  • General Mechanical Requirements:

    ConstraintsCriteria
    All rover configurations must fit within a 1.2m by 1.2m box, with no restrictions to height
    (The rover may be folded/bent/manipulated to fit within said box, but not disassembled) 
    All rover configurations should have a low center of mass, as close to the center of the drivetrain as possible
    Any mission specific rover configuration must weigh less than 50kgRover should run on 48 V power supply (TBD)
    The total weight of all rover parts must weigh less than 70kg 
    The rover must be able to operate in 40C ambient temperature, windy/dust conditions
    and light rain fall

    Goal Range of rover (operating time) must be 1.5 hours
    Rover must fit within team transport trailer
  • Arm Requirements

    ConstraintsCriteria

    The rover must possess a robotic arm capable of performing dexterous operations (i.e. picking up tools, flipping switches, turning knobs, etc.)

    Use O-drive motor controllers on arm
    (Mechanical to look into cooling solutions)

    Robotic arm end effector must be capable of tightening a hex head screw 
    (hex head size has very slightly changed in the past between competitions, with a 5/16" in 2021 and an 8mm in 2019)
    (Screwdrivers may be built into the rover or the rover may use its end effector to pick up screwdriver tools provided at comp)

    Use BLDC motors on entirety of arm

    Robotic arm must possess X degrees of freedom
    (This value will either be 5 or 6, but more research/testing has to be done to figure out this value)
    (Our current arm has 5 degrees of freedom, and so does NASA's Curiosity)
    (Software mentioned having 6 DoF might open up their programming space for IK)

    Arm joints should mechanically support space to use two encoders per joint (one on motor, one on joint)

    Arm's reach must be capable of picking item up off the ground

    Arm should have integrated pathing to route wires with more organization

    Arm must have a minimum lifting capacity of 5kg

    End effector should use a ball head allen key

    Arm must be capable of grabbing and towing a 15mm dia. rope attached to 5kg weight

    Try to use zero servos on the arm to eliminate need for arm PCB
    End effector must be able to grasp objects with a 5cm dia. at a minimum
    End effector must have a minimum precision of 4mm (<half keyboard key)
    Arm must be __ backdriveable (TBD)
    Arm must have one camera to provide end effector footage for operator
  • Drivetrain Requirements

    ConstraintsCriteria
    Drivetrain must support of X wheels (TBD)

    Use O-drive motor controllers on the drivetrain. Wiring from O-drives to motors should be optimiZED


    Discuss direct drive vs chain drive

    Needs to be able to traverse through soft sandy areas, rough stony areas, rocks and boulder fields, vertical drops, and steep slopes

    Determine a max rock height that we want to be able to climb? 


    Determine the typical and maximum forces applied to the rover (i.e. from tall vertical drops, smaller drops, etc.)


    Determine if we need to traverse sandy slopes?
    Must dampen shock felt by the rover to protect system electronics
    Drivetrain must travel at X m/sDetermine minimum speed needed for rocky traversal or determine the typical speed used in URC?
    Drivetrain must have a low centre of gravity 
    • Notes:
      • Consider how drivetrain style increases/reduces turning scrub
      • Look into swerve on wheels

  • Chassis Requirements

    ConstraintsCriteria
    Chassis must support mounting points for science, arm, GPS, ebox, comms equipment,
    Ubiquiti rockets, gimbal, estop, and any cameras/sensors deemed necessary
    Provide easy mounting to the platform to allow for mechanism modularity and other structures to be attached
    Chassis must support LED matrix to show status lights during autonomous missionProvide a vertical structure that allows for mounting at a taller height (i.e. for cameras and the LED matrix)
  • Vision Requirements

    ConstraintsCriteria
    Rover must have an arm camera to provide visual feedback for operators
    Rover must have a top mounted ZED camera 
    Rover must have hardware to support rear view footage for the rover
    LED lights from the rockets must be visible

    -scrapping gimbal system

  • Communications Requirements

    ConstraintsCriteria
    Base station antenna height must not exceed 3m
    Cannot use a camera or other visual feedback to control antenna direction

    -look into antennae spacing on rover (more research tbd, but we probably need to optimize our antennae spacing to avoid interference)

  • Science Requirements

    ConstraintsCriteriaOther Notes
    Full science system must be on board the rover
    Rover may use cameras or other passive instruments to investigate the area
    Chemicals used must be contained on the rover (none spilled on the ground)
    Rover may use a mechanism to dig

Electrical Requirements

Arm


Drivetrain


Science


Gimbal


Base Station


Electrical Box


Misc.


Software/Firmware Requirements

Arm

  • Safety checks
    • Current
    • Position
    • Limit switch
    • Velocity
  • Joint-Level Limits
    • Max Acceleration  Limiting
    • Max Jerk Limiting
  • End-effector Limits(IK Mode)
    • Max Acceleration Limiting
    • Max Jerk Limiting
  • Control Modes
    • Joint Level:
      • Open-loop (controlling voltage duty cycle)
      • Velocity
      • Position
      • Cascaded Control to compensate for gravity and joint inertias
      • Mode switching between all control modes
    • End-effector level(IK):
      • Velocity
      • Position
      • Trajectory Following
    • Be able to move to predefined configuration
      • ex. press a gui button that moves arm to a home position
      • ex. press a gui button that moves arm to a position with low CG suitable for fast driving
  • PID tuning
    • Run time tuning of parameters
    • Characterizing PID performance
      • Graphing out PID Step Responses
  • GUIs:
    • Arm configuration viz
      • Bob wrote one for an old arm, but we could just use our urdf in rviz
    • Arm workspace viz
      • Former user (Deleted)  wrote this thing that can visualize the arm's max reach. 
      • We can overlay this on a camera feed or something. or add a camera feed into rviz

Drivetrain

  • Open loop control
  • Velocity control
  • Hold a position + and offset control?

Science

  • Have a way of grabbing images from the video stream

Autonomy

  • GUI to input list of GPS coordinates
    • should be able to start driving to fist coordinate before full list in input
  • Drive to GPS coordinate
  • spiral search to find AR tag
  • drive towards AR tag
  • Drive between AR tag posts (later stages)
  • Have recovery behaviors for when rover is stuck (ie. in bush)
  • have recovery behavior for when rover has lost comms (ie. backtrack back to last know position that has good comms)
  • Occupancy grid/cost map based off of ZED2 point cloud
  • Implementation details:
    • needs conversion to the correct format
    • TF tree from udrf
    • Behavior within ros2 nav2
    • point clouds from ZED
    • GPS and IMU data from vectornav
    • waypoints from gps gui input
    • AR tag locations from ar_track_alvar

Cameras

  • ZED
    • Upgrade to 720 if possible
    • there's a package that does this already
    • Use ZED2
    • Stream left camera at VGA 15fps
    • Switch to use THEORA codec instead of compressed jpegs
    • Add webrtc streaming support
    • Stream depth
    • Projecting a bird’s eye view of the ZED stream
  • Camera calibration (blackfly, piCam)

Communication

  • Minimum is 2 way load balancing with 900 MHz and 5 GHz
  • Goal is 3 way