Difference between revisions of "DEWBOT VIII Shooter"
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− | 1640's Shooter requirements for Rebound Rumble are: | + | [[image:DB8_MM_120519_csm-26.jpg|350px|right|thumb|Ball leaving shooter at [[DEWBOT VIII Monty Madness|Monty Madness]]]]1640's Shooter requirements for Rebound Rumble are: |
:* This is a shooter; not a dumper | :* This is a shooter; not a dumper | ||
+ | :* Primarily targeting the top basket | ||
:* High scoring reliability (>67%) from Key or closer | :* High scoring reliability (>67%) from Key or closer | ||
:* Ability to feed balls to alliance scoring field from the outbounder station | :* Ability to feed balls to alliance scoring field from the outbounder station | ||
Line 7: | Line 8: | ||
:* Automatic rangefinding & aiming | :* Automatic rangefinding & aiming | ||
:* Maintain low CoM for bridge balancing & preventing bridge tips | :* Maintain low CoM for bridge balancing & preventing bridge tips | ||
+ | |||
+ | The Shooter system comprises: | ||
+ | :# A fixed-geometry overshot wheeled shooter | ||
+ | :# A tachometer to determine and thereby enable control of shooter wheel speed | ||
+ | :# A camera for aiming | ||
+ | :# A [[DEWBOT_VIII_Drive_Train#Drive_Modes | Drive Mode]] specifically for aiming the robot | ||
+ | :# A narrow-beam sonor to determine range to back-board | ||
+ | |||
+ | ==Key Technical Challenges & Statements== | ||
+ | :* A high shooter elevation (trajectory) will be needed to score in the top basket | ||
+ | :* High trajectory shooters shooting from the Key cannot be easily blocked (regardless of shooter height) | ||
+ | :* | ||
+ | |||
+ | ==Concepts== | ||
+ | :* Wheeled shooter was the only serious concept examined (well, there was some catapult testing early) | ||
+ | :* An overshot wheeled shooter offers the desired backspin | ||
+ | :* To manage mass & cost, it was decided early that a decision to use pivot drive (which was subsequently made) would also become a decision to fix the shooter azimuth relative to the chassis. If we use pivot drive, we will aim the robot; we will not use a turret to aim the shooter. | ||
+ | :* The camera should be utilized to adjust azimuth (relative to field). Automatic aiming preferred if (and only if) this could be demonstrated to result in higher scoring than Driver-aimed/Camera-assisted shooting. | ||
+ | :* A narrow-cone sonar was specified to determine distance to backboard | ||
+ | :* The shooter wheels must be speed-controlled | ||
+ | :* The sonar or alternately the operator to supply the set-point for the shooter wheel speed | ||
+ | |||
+ | ==Prototypes== | ||
+ | Prototyping was limited and the final shooter closely resembled the prototype. | ||
+ | <gallery widths=250 heights=250 perrow=3> | ||
+ | Image:DB8_120111_csm-6.jpg|Assembling prototype | ||
+ | Image:DB8_120111_csm-7.jpg|Testing undershot wheel configuration | ||
+ | Image:DB8_120111_csm-9.jpg|Testing overshot wheel configuration | ||
+ | Image:DB8_120112_csm-3.jpg|Prototype mounted on drill press platform | ||
+ | Image:DB8_120114_csm-18.jpg|Testing prototype on [[DEWBOT VI]] chassis | ||
+ | Image:DB8_120128_csm-12.jpg|Testing the integrated [[DEWBOT VIII Ball Collection and Storage|Lift]]/Shooter assembly prototype | ||
+ | </gallery> | ||
+ | |||
+ | ==Design Details== | ||
+ | Power: Fisher Price -9015 motor with BaneBots P60 4:1 reduction gearbox directly driving a pair of 8" kitbot wheels<br> | ||
+ | :3900 unloaded rpm (max)<br> | ||
+ | Shooting Angle: 55° from horizontal (fixed)<br> | ||
+ | Tachometer: Nippon-Denso E6DF motor with custom circuit<br> | ||
+ | :Motor Gearbox, shooter wheels and tachometer are all on a common ½" 7075 Al shaft | ||
+ | |||
+ | ==Control== | ||
+ | |||
+ | ==Issues & Developments== | ||
---- | ---- | ||
− | [[Category:Robot]][[Category:DEWBOT VIII]] | + | [[Category:Robot]][[Category:DEWBOT VIII]][[Category:Photo Galleries]] |
Latest revision as of 00:40, 22 August 2012
1640's Shooter requirements for Rebound Rumble are:- This is a shooter; not a dumper
- Primarily targeting the top basket
- High scoring reliability (>67%) from Key or closer
- Ability to feed balls to alliance scoring field from the outbounder station
- Backspin to drop into basket and provide dead landing upon feeding
- Fast recycle; one shot per second (minimum)
- Automatic rangefinding & aiming
- Maintain low CoM for bridge balancing & preventing bridge tips
The Shooter system comprises:
- A fixed-geometry overshot wheeled shooter
- A tachometer to determine and thereby enable control of shooter wheel speed
- A camera for aiming
- A Drive Mode specifically for aiming the robot
- A narrow-beam sonor to determine range to back-board
Contents
Key Technical Challenges & Statements
- A high shooter elevation (trajectory) will be needed to score in the top basket
- High trajectory shooters shooting from the Key cannot be easily blocked (regardless of shooter height)
Concepts
- Wheeled shooter was the only serious concept examined (well, there was some catapult testing early)
- An overshot wheeled shooter offers the desired backspin
- To manage mass & cost, it was decided early that a decision to use pivot drive (which was subsequently made) would also become a decision to fix the shooter azimuth relative to the chassis. If we use pivot drive, we will aim the robot; we will not use a turret to aim the shooter.
- The camera should be utilized to adjust azimuth (relative to field). Automatic aiming preferred if (and only if) this could be demonstrated to result in higher scoring than Driver-aimed/Camera-assisted shooting.
- A narrow-cone sonar was specified to determine distance to backboard
- The shooter wheels must be speed-controlled
- The sonar or alternately the operator to supply the set-point for the shooter wheel speed
Prototypes
Prototyping was limited and the final shooter closely resembled the prototype.
Design Details
Power: Fisher Price -9015 motor with BaneBots P60 4:1 reduction gearbox directly driving a pair of 8" kitbot wheels
- 3900 unloaded rpm (max)
Shooting Angle: 55° from horizontal (fixed)
Tachometer: Nippon-Denso E6DF motor with custom circuit
- Motor Gearbox, shooter wheels and tachometer are all on a common ½" 7075 Al shaft