Voltage Torque Conversion Software

Description

The Voltage Torque Conversion Software is a flight software module that translates voltage commands into motor torque commands. This conversion is essential for interfacing command and control systems with electromechanical actuators such as reaction wheels, control moment gyroscopes, and deployment mechanisms. The module applies configurable gain, scale factor, and bias parameters to each motor channel, enabling accurate modeling of motor driver characteristics and calibration errors.

Example Use Cases

Reaction Wheel Control: Convert voltage commands from an attitude controller into torque commands for reaction wheel motors.
Mechanism Actuation: Translate driver voltage signals into torque commands for deployment or articulation motors.
Hardware-in-the-Loop Testing: Model motor driver electronics for closed-loop simulation with flight software.

Module Implementation

The Voltage Torque Conversion Software is a Software component that processes an array of voltage commands and produces corresponding motor torque commands.

Conversion Equation

For each motor channel $i$ , the torque is computed as:

τ_{i} = K_{i} \cdot S_{i} \cdot V_{i} + B_{i}

where:

$τ_{i}$ is the output motor torque [N·m]
$K_{i}$ is the voltage-to-torque gain [N·m/V]
$S_{i}$ is the scale factor [-]
$V_{i}$ is the input voltage command [V]
$B_{i}$ is the torque bias [N·m]

Default Values

If a parameter array has fewer elements than the number of motors, default values are applied:

Parameter	Default Value
Gain ( $K$ )	0.0
Scale Factor ( $S$ )	1.0
Bias ( $B$ )	0.0

Parameter Applications

The parameters enable modeling of various motor driver characteristics:

Parameter	Physical Interpretation
Gain	Motor torque constant and driver amplification
Scale Factor	Calibration errors or intentional gain adjustments
Bias	Residual torque offsets or friction compensation

Assumptions/Limitations

The conversion is linear; nonlinear motor characteristics such as saturation or dead zones are not modeled.
Parameter arrays are indexed by motor number; mismatched array lengths use default values for missing elements.
The output array is resized to match the input voltage array length at each update.
No filtering or rate limiting is applied to the torque