Software Architecture

This page outlines the software modules, sensor feeds, and control flows running on the ART26 Formula Student vehicle.

1. High-Level Software Architecture Diagram

The software architecture is divided into decoupled functional blocks that communicate asynchronously via the CAN bus.

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2. Core Software Functional Blocks

Dashboard

• CAN Interface: Subscribes to critical CAN IDs from other boards.
• UI Engine: Renders the driver screen over TouchGFX for a high-refresh TFT LCD Screen.
• User Inputs: Publishes touch panel inputs back onto the CAN bus (e.g. settings changes, page navigation).

Vehicle FSM

Manages the safety-critical state machine transitions of the vehicle:

• Startup Sequence: Wait for R2D (Ready to Drive) button -> Run precharge -> Manual R2D Activation (brake + button) -> Control Loop.
• Diagnostics: Runs background tasks for Timeout watchdogs and SDC/SCS watchdogs to instantly catch sensor implausibilities or communication loss.

Motor Control & Torque Vectoring

Runs real-time traction and stability control algorithms:

• Inputs: Subscribes to GPS, IMU, Wheel Speeds, Steering Angle, and Pedal Position sensors.
• UKF Algorithms: Runs Unscented Kalman Filter algorithms for vehicle state estimation (slip angle, velocity, etc.).
• Torque Vectoring: Calculates individual torque targets for the Left Inverter and Right Inverter to optimize cornering dynamics.
• Outputs: Publishes inverter commands and internal algorithm variables for logging.
• Safety: Runs dedicated Timeout watchdogs to shut off inverter torque if command packets are delayed.

Inverter Programming

Provides a diagnostics interface to flash or configure the inverters:

• Subscribes to CAN programming IDs.
• Enables passthrough mode on the Galvanic Isolators.
• Converts CAN bus commands to RS232 communication directly required by the inverter programming interface.

Sensor Processing

Processes raw analog signals from physical gateways:

• Uses DMA (Direct Memory Access) to perform oversampling of ADCs from Gateways without blocking CPU execution.
• Runs Kalman Filters to denoise sensor signals (like suspension travel and throttle inputs).
• Publishes refined physical values onto the CAN bus.
• Integrates runtime recalibration drivers to tare sensors on the fly.

Telemetry & Logging

Ensures all vehicle data is recorded and broadcasted:

• Subscribes to all CAN messages.
• Builds a formatted CSV-style telemetry string.
• SD Logger: Buffers the CSV strings in RAM for high-throughput write operations to the physical SD Card.
• Wireless Broadcast: Packages and transmits telemetry packets over UDP to the pit lane receiver via Wi-Fi/LTE.

RTK GPS

• Listens to UART traffic using DMA to offload parsing overhead.
• Decodes the custom KSXT NMEA sentences.
• Publishes precise vehicle coordinates, heading, and speed on the CAN bus.
• Computes real-time lap timings on the board.

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3. Monitored Sensors List

Our control units ingest and process data from the following sensors:

• IMU (Inertial Measurement Unit): 6-DOF acceleration and angular rates.
• RTK GPS: Centimeter-level positioning and heading.
• Hall Wheel Speed Sensors: Angular speeds of the four wheels.
• Suspension Travel Sensors: Linear potentiometers to measure damper displacements.
• APPS (Accelerator Pedal Position Sensors): Dual redundant throttle sensors.
• Brake Pressure Sensors: Front and rear brake line pressures.
• Liquid Temp Sensors: Coolant temperatures in the motor and accumulator loops.
• Liquid Flow Sensors: Flow rates in the cooling loops.
• Current Sensors: High-voltage tractive system and low-voltage battery currents.