StabilityCompensation_MDD

Module -- Stability Compensation

High-Level Description

This function provides in-vehicle stability of EPS behavior. To maximize steering feel, the function blends between two different tunings based on vehicle speed and low frequency handwheel torque. Because system gains may get multiplied by various scale factors, either from serial communications or from other software functions, this function provides a second blending feature.

Some vehicle programs require a secondary, or "systematic", calculation of stability compensation followed by a correlation check. The systematic calculations usually must reside in a separate Memory Partition Unit (MPU), and switching between MPUs negatively impacts system throughput. This model is designed using the best-known implementation at this time.

Figures

Component Diagram

Variable Data Dictionary

For details on module input / output variable, refer to the Data Dictionary for the application. Input / output variable names are listed here for reference.

Module Internal Variables

This section identifies the name, range and resolutions for module specific data created by this module. If there are no range restrictions on the variable, the term “FULL” is placed into the table for legal range.

* See unit testing notes in section 2.3.1 for range considerations of Notch Filter

Notch filter Unit testing considerations

Since the notch filter implementation used in this module is dynamic in nature, absolute ranges are difficult to determine without pre-defined knowledge on the combination of coefficient values (A1, A2, B0, B1, B2). Because of this, the systems group ran simulations on 10 different combinations of coefficients (2 with defined default calibrations, 8 considered extreme cases of notch filters) and logged the ranges of the filter state variables and outputs during a frequency sweep. The ranges given throughout this module were taken as the worst case results of all of the given test cases.

To provide useful cases for unit testing, the boundary checks tested during unit testing should be altered to test the state variable minimum and maximum for each of the 10 test cases with the given coefficients set to the values given in that test case. In the case where the default values of the coefficients are used in a vector, the unit tester should not test the corresponding state variables with values over the range defined for that set of coefficients. See attached simulation results.

User defined typedef definition/declaration

This section documents any user types uniquely used for the module.

Constant Data Dictionary

Calibration Constants

This section lists the calibrations used by the module. For details on calibration constants, refer to the Data Dictionary for the application.

Program (fixed) Constants

Embedded Constants

All embedded constants whose values are provided in Eng units will be evaluated to the equivalent counts by using the FPM_InitFixedPoint_m() macro within the #define statement.

Local

Global

This section lists the global constants used by the module. For details on global constants, refer to the Data Dictionary for the application.

Module specific Lookup Tables Constants

(This is for lookup tables (arrays) with fixed values, same name as other tables)

Functions/Macros used by the Sub-Modules

Library Functions / Macros

The library and functions / Macros that are called by the various sub modules are identified below,

1. FPM_FloatToFixed_m

2. Limit_m

3. NF_Init_f32

4. FPM_FixedToFloat_m

5. BilinearXYM_u16_u16Xu16YM_Cnt

6. IntplVarXY_u16_u16Xu16Y_Cnt

7. Blend_f32

8. Abs_f32_m

Data Hiding Functions

1. <None>

Global Functions/Macros Defined by this Module

None

Local Functions/Macros Used by this MDD only

ApplyStabilityComp

* See unit testing notes in section 2.3.1 for range considerations of Notch Filter

Description

Software Module Implementation

Runtime Environment (RTE) Initial Values

This section lists the initial values of data written by this module but controlled by the RTE. After RTE initialization, the data in this table will contain these values.

Initialization Functions

Init: StabilityComp_Init1

Design Rationale

None

Periodic Functions

Per: StabilityComp_Per1

Design Rationale

Program Flow Start

Rte_Call_StabilityComp_Per1_CP0_CheckpointReached()

Store Module Inputs to Local copies

N/A

Store Local copy of outputs into Module Outputs

Rte_IWrite_StabilityComp_Per1_AssistCmd_MtrNm_f32(AssistCmd_MtrNm_T_f32)Program Flow End

Rte_Call_StabilityComp_Per1_CP1_CheckpointReached()

Fault Recovery Functions

Shutdown Functions

Interrupt Functions

Serial Communication Functions

Execution Requirements

Execution Sequence of the Module

(Describe in words relevant details about the execution sequence of the different sub modules.)

Execution Rates for sub-modules called by the Scheduler

This table serves as reference for the Scheduler design

Execution Requirements for Serial Communication Functions

Memory Map Definition Requirements

Sub Modules (Functions)

This table identifies the software segments for functions identified in this module.

Local Functions

This table identifies the software segments for local functions identified in this module.

Known Issues / Limitations With Design

1. INLINE functions defined in GlobalMacro.h are not unit tested

Revision Control Log