MATLAB REAL-TIME WORKSHOP EMBEDDED CODER - S Bedienungsanleitung PDF herunterladen (Seite 27)

5 Haldex Traction Specific

Requirements

In this chapter specific Haldex Traction requirements are investigated in both

TargetLink and Real-Time Workshop Embedded Coder.

Haldex Traction uses a practical approach to have several parameter sets which

the user can change before driving and during runtime. These parameters are

saved in a so called pdc-file which is programmed by Haldex Traction to access

the parameters during runtime. The parameters sets are saved in vectors in the

pdc-file. By calling the right index in the vectors, the desired parameter set is

chosen.

Example:

If parameter sets are saved in the vectors ref1= [5 6 7] and ref2= [3 9 5] then

parameter ref1 can have the value 5, 6 or 7 while ref2 can have the value 3, 9 or 5.

The user can access the parameters by a call for param1 = ref1[nbr] and param2 =

ref2[nbr] where nbr is the index of the desired parameter set , 0, 1 or 2 in this

example. By simply changing the value of nbr in one place in the code, the whole

set is changed everywhere the parameters are called in the entire code.

It is also desired to make variables calibratable in order to be able to change the

parameters via a calibration system. Calibration systems access variables directly

by their addresses in the ECU memory.

5.1 TargetLink

TargetLink offers so called variant coding to handle parameter sets. There are two

types of variant coding: data variants and code variants. The user can assign

different values to a variable during runtime while code variant is to assign

different data types or scaling parameter to a variable during code generation

time. For Haldex Traction data variant is the interesting kind of variant coding. In

the generated code all variables belonging to one data variant item, one parameter

set, are collected in a struct. An example is shown below [3]:

One instance of the structure above is generated for each variant item, that is one

structure for each parameter set. There are two variant coding styles that are

typedef struct Vca DV tag

{

const volatile UInt8 param1;

const volatile UInt8 param2;

const volatile UInt8 param3;

} Vca_DV_tp;/*Struct data type for data variant

configuration DV*/

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MATLAB REAL-TIME WORKSHOP EMBEDDED CODER - S Bedienungsanleitung Seite 27