Build to kick kick to win. Shooting skills 2 Outline Shooting mechanism System description Actuator...
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Transcript of Build to kick kick to win. Shooting skills 2 Outline Shooting mechanism System description Actuator...
Build to kick kick to win
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Shooting skills
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Outline
Shooting mechanismSystem descriptionActuator design
Lob shotsIdentificationCalibration
Towards controlled shootingProblem descriptionProposed implementation
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Shooting mechanism
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Requirements and specifications
Requirements:• Controllable• Hard / soft• Lob / flat• Repeatable
Specifications• vf = 9ms-1
• xf = 90 mm
• tf = 20 ms• a ≈ 450 ms-2
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System description
Robotbattery
DC DC
ActuatorMechanicaltransmission
BallC
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Actuator design
Mechanical design
Electromagnetic design
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Actuator design
Investigated aspects• Saturation• Eddy currents• Losses• Thermal issues
2.4T
1.5T
Meessen, K.J., Paulides, J.J.H. & Lomonova, E. (2010). A football kicking high speed actuator for a mobile robotic application. Proceedings of the 36th Annual Conference of the IEEE Industrial Electronics Society, IECON 2010, 7-10 November 2010, Glendale, Arizona, (pp. 1659-1664).
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Actuator design
Final design• Total mass: 4.5 kg• Peak force: 700N• Peak current: 110A
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Outline
Shooting mechanismSystem descriptionSolenoid actuator design
Lob shotsIdentificationCalibration
Towards controlled shootingProblem descriptionProposed implementation
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Lob shots: trajectory
Largest gradient possible
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Lob shots: identification
Each actuator has its own actuator characteristic
General function between distance and duty cycle:
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Lob shots: calibration
Measure distance • For accurate fit at least 3
measurements are necessary
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Lob shots: calibration
Manual calibration using a Matlab gui• For accurate fit at least 3 measurements
are necessary
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Lob shots: tuning
The perfect lob shot• Shoot just under de goal crossbar • Lob trajectory depends on distance ball to the goal
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Lob shots: tuning
The perfect lob shot• Shoot just under de goal crossbar • Lob trajectory depends on distance ball to the goal
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Outline
Shooting mechanismSystem descriptionSolenoid actuator design
Lob shotsIdentificationCalibration
Towards controlled shootingProblem descriptionProposed implementation
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Problem description
Increasing ball output speed accuracy• Currently a large variation between Turtles
– Makes tuning difficult
• Current relation between kick-effort and ball output speed is not linear– Also increases tuning complexity
• Current system is open-loop– Tuning per Turtle is possible, though time consuming
• Desired: more predictable behavior– Tuning effort/time decreases– More linear behavior– Decrease of variation between Turtles
Proposed implementation
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Ball
Encoder
Solenoid
Plunger
Lever
Amplifier +Actuator
Control algorithm
Encoder
PC + IO stack
PWM signal
Encoder value
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Proposed implementation
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Proposed implementation
Controlling the lever speed• Both time and encoder resolution
pose limitations• Due to design of solenoid 'braking' is
not possible: speed overshoot is not allowed
• Main idea is to 'guide' lever + ball to end speed, instead of kicking/hitting
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Proposed implementation: simulation
Current situation
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Proposed implementation: simulation
Proposed solution
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Summary and conclusions
• Design and optimization of the shooting mechanism
• Identified an exponential relation between the duty cycle and kicking distance for lob shots
• Lob shot calibration using an graphical user interface
• Feedback control design for the output speed of the ball
• Modeling and simulation of the feedback controlled shooting mechanism
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Thank you for your attention