Build to kick kick to win

Shooting skills 2

Outline Shooting mechanism System description Actuator design Lob shots Identification Calibration Towards controlled shooting Problem description Proposed implementation 3

Shooting mechanism 4

Requirements and specifications Requirements: Controllable Hard / soft Lob / flat Repeatable Specifications v f = 9ms -1 x f = 90 mm t f = 20 ms a 450 ms -2 5

System description 6

Actuator design Mechanical design Electromagnetic design 7

Actuator design Investigated aspects Saturation Eddy currents Losses Thermal issues 2.4T 1.5T 8 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 ).

Actuator design Final design Total mass: 4.5 kg Peak force: 700N Peak current: 110A 9

Outline Shooting mechanism System description Solenoid actuator design Lob shots Identification Calibration Towards controlled shooting Problem description Proposed implementation 10

Lob shots: trajectory 11 Largest gradient possible

Lob shots: identification 12 Each actuator has its own actuator characteristic General function between distance and duty cycle:

Lob shots: calibration Measure distance For accurate fit at least 3 measurements are necessary 13

Lob shots: calibration Manual calibration using a Matlab gui For accurate fit at least 3 measurements are necessary 14

Lob shots: tuning The perfect lob shot Shoot just under de goal crossbar Lob trajectory depends on distance ball to the goal 15

Lob shots: tuning The perfect lob shot Shoot just under de goal crossbar Lob trajectory depends on distance ball to the goal 16

Lob shots: tuning Each kicker has different characteristics At least 3 measurements per turtle: 15 measurements required 17 Future work Calibration using the kinect Parameterization Duty cycle in function of height and distance

Outline Shooting mechanism System description Solenoid actuator design Lob shots Identification Calibration Towards controlled shooting Problem description Proposed implementation 18

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 19

Proposed implementation 20 Ball Encoder Solenoid Plunger Lever Amplifier + Actuator Control algorithm Encoder PC + IO stack PWM signal Encoder value

Proposed implementation 21

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 22

Proposed implementation: simulation 23 Current situation

Proposed implementation: simulation 24 Proposed solution

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 25

Thank you for your attention 26