Rapid Prototyping with the Controller Area Network (CAN)

Abstract

Rapid Control Prototyping (RCP) tools are becoming an essential part of the development process of modern automotive control strategies. The interface between the RCP real-time hardware and the existing electronic control unit (ECU) can be established via Controller Area Network (CAN). In a typical production ECU, the limited availability of unused message objects and the rate of data transfer on the CAN bus are limiting factors which influence the mechanism used for communication between the ECU and the RCP system. This document outlines the details involved in a CAN-based selective bypass approach. A data transfer mechanism is proposed which makes use of only two message objects to establish communication. The introduced time delays and the synchronization of the time driven main tasks are discussed. The proposed mechanism is validated through engine testing and the implementation details are described as well. A standard realization of the proposed mechanism is presented based on the CAN Calibration Protocol (CCP) standard. The CAN-based approach to RCP is shown to be a viable alternative to a Dual Port RAM (DPRAM)-based approach, especially in light of the fact that the hardware flexibility is maintained when the original ECU is being upgraded.

Parameterization and Transient Validation of a Variable Geometry Turbocharger for Mean-Value Modeling at Low and Medium Speed-Load Points

“…In order to reduce measurement errors due to improper sampling, these signals are sampled each crank degree and then averaged over each engine cycle before low passing them. The ECU is bypassed via a CAN interface as described in [12]. This allows access to internal variables of the ECU and control over the engine via a dSPACE rapid prototyping system, which is also used for the data acquisition.…”

Model-based control algorithm development of induction machines by using a well-defined model architecture and rapid control prototyping

“…In this case, only a specific part of the control algorithm is executed on the RCP target computer, which is connected to the ECU through a dedicated communication interface. This configuration is usually called as ECU bypass, and the dedicated communication interface as the ECU bypass interface [21][22][23][24][25].…”

“…Textbook [24] describes RCP as a method applied typically for ECU bypassing and presents an application example related to engine control development. Study [25] discusses various RCP applications, especially ECU bypassing over CAN. RCP is applied in control development of electric drive systems as well.…”