Servo Control Gayatri Sagi Shadab Ambat Jeannette Djigbenou

Servo Control • • Gayatri Sagi Shadab Ambat Jeannette Djigbenou Vamsikrishna Gudivada

Objectives Design a Software to take five signals from piccolo and transmitting them to the specific servos via CAN bus. Piccolo µC 1 TIM µC 2 CAN TIM Servo

Requirements • Minimum servo update rate - 20 ms to 50 ms. • Capture and translate PWM and retransmit as CAN packets. • Drive system servos (PWM) using respective CAN packets. • The pulse width of Servo signal is 0. 5 ms to 2. 5 ms with a frequency of 20 Hz to 50 Hz.

Requirements • The different CAN packets sent are Rudder, Elevator, Throttle, Aileron and heartbeats as Servo Producer, Servo Consumer 1, Servo Consumer 2 and Servo Consumer 3.

Design Nosewheel servo PWM Piccolo µC 1 TIM Rudder Servo µC 2 CAN µC 2 TIM 1 TIM 3 Throttle Servo µC 2 TIM 2 PWM Elevator Servo Left Aileron Servo PWM Right Aileron Servo

Design • Interfacing the servo with the microcontroller using TIM (Tiny Interface Module) • Programming the microcontroller to capture pulse width from the input (Piccolo) using PCA capture (Programmable Counter Array) and places on the CAN (Control Area Network).

Design • Another Microcontroller receives the data on the CAN and controls the servos by providing pulses. • Four to Six servos can be controlled by each microcontroller on TIM (Tiny Interface Module).

Design TIM

Budget • 4 x TIM • 6 x Servo Futaba s 3010 TIM Weight Size Current 12 g Size: 1. 875 X 1. 625 X < 87 m. A. 5 Inches

Budget Servo Futaba s 3010 Weight Size Current Speed 1. 4 oz Size: 40 x 20 > 2 A Torque/Speed @ (41 g) x 39. 1 mm 6. 0 V: 0. 16 sec

Risks • Timing issues: – Lag introduced due to PWM to CAN conversion. – Lag introduced due to CAN to PWM conversion. – Lag introduced due to CAN bus handling of produced packets.

Risks • Power issues: – Testing needs to be done to see the average power consumed by the system during a simulation run to verify servo power consumption.

Risks • Debugging needs to continue on the TIM to ensure that it behaves as intended by the programming/design. Could be prone to errors since it has sustained less time of use/testing than using a commercially produced development board.

Recommendations & Status • Assisted in the design of TIM. • Programmed for capturing the pulses for the servos from the piccolo.