Systems Engineering

The machines we build combine processes across multiple domains, most frequently including mechanical forces, electrical signals, and computational processes. In many cases, the system boundaries themselves include one or more human or non-human users, opening the door to unbounded complexity.

In more general form, this list can be extended much further. It might include physical processes such as acoustics, pneumatics, and hydraulics. It could include higher-order computational processes such as distributed or networked computing.

There are many established interdisciplinary fields which address the question of engineering a complex multi-domain system: robotics, mechatronics, operations research, human-computer interaction, control theory, software engineering, and more.

This course can’t begin to address the full scope of questions which emerge, but it may be useful to narrow in on specific considerations which apply in the domains we usually encounter.

System Design Prompts

A practical starting point is to organize and enumerate typical design questions. The following categories are drawn from examples of past student projects in the course. N.B. this is a work in progress, this is by no means comprehensive.

Machine Design

  1. What machine subsystems provide mobility in whole or in part?

    1. axles and wheels

    2. turntables

    3. legs

    4. serial-chain joints (e.g. robot arms)

    5. animate articulations (e.g. moving parts intended for humans to see)

  2. What functional tasks does the machine solve?

    1. self-mobility

    2. material transport

    3. object constraint or capture

    4. water transfer, flow, and constraint

    5. active sensing

  3. What structural elements and form are necessary to support the tasks?

    1. rigid frameworks

    2. boxes and enclosures

    3. electronic and wiring mounts

  4. How are the following abstract machine functions implemented?

    1. energy storage (e.g. springs, counterweights, flywheels)

    2. power transmission

    3. motion amplification and reduction

    4. sensing and information transduction

    5. mechanical computation and feedback

    6. self-protection (e.g. limit stops, enclosures)

Design for Humans

In general, what elements of the system are included specifically for humans?

  1. What kinds of information need to be communicated?

    1. discrete events or instructions

    2. continuous state or parameter input

    3. conscious control vs ambient or subconscious input

    4. symbolic vs literal

    5. human to human

    6. instructions

  2. What physical user interface elements are required?

    1. grasping affordances: elements requiring a grasp

      • control: knobs

      • transport: handles

      • manipulanda: graspable objects

    2. non-prehensile affordances: elements requiring a touch or contact

      • buttons and toggle switches

      • pressure pads, e.g. force-sensitive resistors (FSR) or strain gages

      • capacitive panels

    3. non-contact affordances

      • microphones

      • range sensors (acoustic or optical)

      • shadow sensors

      • cameras

  3. What user interface behaviors are required?

    1. direct user feedback (output with no other functional purpose)

      • sound production

      • illumination and lighting

      • symbolic display

    2. indirect user feedback (implicit in solving a task)

      • motion trajectory variation

      • tempo changes and pauses

  4. What aspects of the system require practice or training?

  5. What elements of form involve consideration of human needs?

    1. visual and tactile design aesthetics

    2. paint and patterning

    3. representational and symbolic form