The goal of the effort sensing team is to take the measurements necessary to determine the effort input by the user. The system must be able to distinguish between user applied forces and system applied forces to ensure the mathematical model has the information to determine the output force that needs to be applied based on those different inputs. This ensures the effort sensing system can provide accurately calculated output to communicate the input to the other subsystems. The specifications below relate to the timeliness and accuracy of these measurements. For all sensor sampling rate constraints, further development is required to determine appropriate sampling rates. The specific metrics for sampling rates are unknown, but these rates should be maximized.
Table 4: Effort Sensing Team Specification and Metrics
| # | Metric/Specification | Minimum Value | Maximum Value | Unit | Maximize /Minimize/ Target/Constraint | Constrained Max/Min |
| ES1 | Sampling rate of 9DOF measurement system | ∞ | Maximize | |||
| ES2 | Sampling rate of strain gauge measurement system | ∞ | Maximize | |||
| ES3 | Response time to call to the propulsion system | 0 | Minimize | Necessary | ||
| ES4 | Response time to register user input from user to the joystick | 0 | Minimize | Necessary | ||
| ES5 | Percent error in angle measurement | 0 | Minimize | |||
| ES6 | Percent error in strain measurement | 0 | Minimize | |||
| ES7 | Cost | 0 | Minimize |
ES1. The sampling rate of the 9 degree of freedom, or 9DOF, measurement system must be fast enough to ensure data is collected quickly enough for the system to provide an output for the angle and orientation of the chair in space. This ensures the 9DOF measurement system can provide timely output to communicate the input to the other subsystems.
ES2. The sampling rate of the strain gauge measurement system must be fast enough to ensure data is collected quickly enough for the system to provide an output for the force of the wheel add-on on the chair. This ensures the strain gauge measurement system can provide timely output to communicate the input to the other subsystems.
ES3. The response time to call the propulsion system must be fast enough to ensure the propulsion system can make adjustments based on input to operate efficiently. This ensures the propulsion system can use the data to respond as designed.
ES4. The response time of registering user input from the joystick must be fast enough to ensure the 9DOF measurement system can correctly implement the mathematical model based on the input to efficiently generate output. This ensures the effort sensing subsystem will be able to generate outputs quickly based on the input from the electro-mechanical integration subsystem.
ES5. The percent error in the angle measurement of the wheelchair must be minimized to ensure the 9DOF measurement system’s mathematical model can produce outputs accurately.
ES6. The percent error in the strain measurement of the wheelchair must be minimized to ensure the strain gauge measurement system’s force calculation is accurate and can be correctly imputed into the other 9DOF measurement system.