Vehicle follow control function: supervisory and dynamic control: design and proof-of-concept by rapid control prototyping

Abstract

This technical report presents the design and implementation of a Vehicle Follow Control (VFC) func-tion. The main goal of the project focuses on the Proof-Of-Concept of the functional behavior by Rapid Control Prototyping. First, the problem was analyzed by making a feasibility analysis; taking into account the challenges involved, necessary tools, methods and technology available. Second a requirement elicitation process was carried out using the CAFCR method. The Product Creation Process (PCP) followed at the compa-ny was analyzed and used to obtain the customer wishes related to the function. In addition, the relevant stake-holders were identified and a context diagram was created to define the scope. Use case scenarios were proposed to obtain the desired functionality, which served as an input to formulate the VFC Sys-tem Requirements. Subsequently, the architecture for the design was proposed, where different software components were identified. The controller design consists of four major components: Supervisor con-troller, Governor, Splitter and Hill Holder. The Supervisor controller was designed based on the func-tional requirements, using the company’s heuristic approach to design state-flow charts. The Governor was designed using a combined distance/speed control approach. The design of the Splitter was carried out by splitting the control signals to the respective vehicle actuators. Finally, the design of the Hill Holder was performed using a state-flow chart and a vehicle model. This was done by estimating the amount of force needed to prevent the vehicle from moving when driving on a hill. The controller was designed using Matlab, and implemented in the prototype vehicle using dSPACE HW/SW. A radar target filter algorithm was designed to properly filter the data coming from the radar and to detect the target vehicle to follow. The Verification and Validation phase was carried out according to the V-cycle model. A series of test cases were run with the vehicle to assess whether the functionality meets the requirements, and whether it fulfills the customer wishes. It was concluded that the RCP platform created for this project provides an important contribution for the company, since it can be used for the integration with other functions involving longitudinal control, which is included in the road map for future autonomous driving