Taking on a Large Project

Getting Started

1. Identify a leader, the leader is designated to:
   • Define problem
   • Break bigger problems down into smaller tasks
   • Assign specific tasks into individuals
   • Track progress (who does what etc.)
2. Sketch and plan the solution
   • Identify all necessary components
   • Create SimuLink model and block diagrams
   • Identify time management
     • When are tools are unavailable
     • Delay mitigation

By this time, we should know what needs to be done.

1. Review the theory for all the tasks
   • Motor
     • Components
     • Principles of operation
   • Mechanical
     • Sensors
     • Joints
     • Commutation
   • Control
     • Real-time programming
     • PID Control
     • System Modelling
   • Electronics
     • Digital
     • Power
2. Logbooks
3. Keep track of progress (GitHub and Trello)
4. Build on success
   • Start simple and add incremental features at a time

Challenges

Motor Group

Rotary

Number of poles are important part of the design. Poorly designed motor with bad choice of number of poles can cause cogging, which “eats up” torque.

Mechanical Design

Mounting points are need to be in consideration for components such as motors, load, and sensors. Consider friction and binding. Radial load is the load along the radial axis acted on the motor shaft. The trust load is the load along the length-axis of the shaft. Constraints to limit these loads are required.

Electrical Designed

High currents causes sparking when communication happens. Open circuit inductors causes sparking. Switching logic for the motors. Position sensing for the motors.

Stubs and Drivers

Control Group

A microcontroller need to be picked. The control frequency for which everything is consistent of is important. Filtering of derivative signals (from high-frequency noise). Design homing procedures of relative sensors.

A simulation is required to understand the models and identify the parameters.

For electronics, specify interconnections. Don’t overlook heat sinks if they are required.

Develop PWM and Encoder Logic. It’s important to distinguish which specific tasks need to be implemented in software or hardware. The more stuff needs to be done in software, the lower the control frequency.

Stubs and Drivers

Stubs include current driver. Scopes and LEDs can be used to test is.

Drivers include encoders. The desired paths that is output from the controller.