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Hybrid System

May 01, 2026

Mechanical Design Brushless Motor Controls Embedded Systems

Hybrid test platform pairing a small inline 4 engine with a brushless motor/generator, sensor network, embedded controller, and safety-focused state machine control.

System Overview

The hybrid system combines a small inline 4 engine, a BLDC motor/generator, battery management, cooling, load control, and data logging into one testbed. The main sensor set includes engine, BLDC, and cooling-system thermistors, current and voltage sensors for both load and generator sides, a load cell for fuel-consumption measurement, and tachometers for the generator and load.

Hybrid System high-level architecture diagram showing main sensors, HCU/BMS data path, H7 router, engine, generator, cooling system, load, and hardware outputs.

Physical Test Platform

The physical setup is built around an engine mounted to a rigid test frame with the brushless motor/generator coupled to the output side. The goal is to evaluate how the engine and electric machine can share power production while keeping the mechanical packaging serviceable and measurable.

Hybrid System physical test rig showing the small inline 4 engine coupled to a brushless motor/generator.

Electronics Box Wiring

The electronics box brings together terminal blocks, shielded cabling, power distribution, sensor connections, and controller interfaces so the test rig can be wired cleanly and serviced during experiments.

Hybrid System electronics box wiring with terminal blocks, shielded cabling, and power distribution.

Electronics and Noise Control

The enclosure is designed to reduce electrical noise in the sensor signals. It uses shielded and grounded CAT6 wiring, filter capacitors where needed, and RC filtering on thermistor lines to improve sensor stability.

Hybrid System electronics box layout with controller boards, sensor interfaces, filter circuits, and power modules.

Control Structure

The control structure separates data fetching, state updates, and timer-driven control updates. The main loop handles new data, control-loop timing, soft errors, hard errors, stop commands, and shutdown behavior.

Hybrid System control structure diagram showing the main loop, data updates, control updates, soft error path, hard error path, and shutdown behavior.

State Machines and Error Handling

The control architecture is organized around subsystem state machines. The state flow covers idle, startup, engine running, power generation, cooldown, manual mode, error handling, and reset behavior.

Hybrid System subsystem state machine diagram showing idle, startup, engine running, generating power, cooldown, manual mode, and error states.

Sensor Filtering

The signal-processing work includes live filtering of noisy temperature data so the controller can work with cleaner thermistor readings instead of raw sensor noise.

Hybrid System live filtering plot showing noisy sensor data being filtered for cleaner thermistor readings.

Servo Throttle Simulation

The servo simulation compares a feedforward oscillation against a simulated proportional controller response to evaluate smoother throttle feathering behavior.

Hybrid System simulated servo throttle plot comparing feedforward oscillation against a proportional controller response.