Aftertreatment Control Unit

ACU

The control unit is used to control and monitor all functions and active components of the exhaust gas aftertreatment system, such as the heating element, the exhaust gas flap and the dosing systems. The associated software covers the control strategies required to meet the respective emission targets. There is no active intervention in the engine control system.

Interfaces of the control unit:

  • Three CAN interfaces (high-speed CAN, configurable 125 kBaud – 500 kBaud) for transmitting the necessary engine data (exhaust gas mass flow, exhaust gas temperature, load, speed, engine temperature, ambient temperature, nitrogen oxide and residual oxygen content if available)
  • Inputs for recording the measured values of the individual sensors

The implementation of the software is model-based using the Matlab Simulink/Stateflow and dSpace Targetlink tool chain. This enables a high level of transparency of the functions and ensures the necessary flexibility of the software. The use of a modular software concept enables an optimally scaled system for all customer requirements. Only the software functions required in the respective application are activated in the overall software.

Based on the known requirements profile, in particular the emission and diagnostic targets and the resulting system configuration, initial data is provided that is of sufficient quality for the first tests on test benches and test vehicles. This forms the basis for short development times.

Technical data

  • Dimensions: 235 x 195 x 50mm
  • Weight: approx. 1kg
  • Protection class: IP67 / IP 69K
  • Supply voltage: 6 – 32V, reverse polarity protected
  • Power consumption: in operation < 130mA, in standby < 0.1mA
  • Operating temperature range: -40 °C to 105 °C (air-cooled)
    +125 °C (fuel-cooled)
  • Service life: > 20,000 operating hours or 15 years
  • Safety Integrity Level (SIL): Level 2
  • 3x CAN (High-Speed (ISO 11898-2, SAE J1939-11, High-Speed)
  • On-board interface for evaluating a lambda sensor
  • Switchable peripheral supply for the actuators (80A)
  • On-board diagnostics OBD II (SAE J1939-73, ISO 15031-5 (SAE J1979), ISO 27145 (WWH-OBD)
  • Off-board diagnostics: UDS (ISO 14229) and KWP2000 (ISO 14230)
  • Mechanical strength up to vibration: 9g, and shock: 50g