4.28. Vehicle Speed Processing Manager - VehSpdProcg

• Overview

• Functions

• Ports

• Parameters

Id	VehSpdProcg
Version	0.5.0.0
Title	Vehicle Speed Processing Manager
System	Drivetrain
Document Type	Application Software Component Specification Preview

4.28.1. Overview

The Vehicle Speed Processing component arbitrates between an external vehicle speed input and an internal calculation of vehicle speed based on wheel speeds considering the validity of the external input. It provides the signed vehicle speed, filtered signed vehicle speed, vehicle speed validity, and standstill flag as outputs. The component also performs error checks and fault handling.

4.28.2. Functions

Title	Description
Vehicle Speed Arbitration	Arbitrates between wheel speed sensor signals and external vehicle speed signal to determine the final vehicle speed output. The arbitration method is configurable.
Vehicle Speed Filtering	Filters the arbitrated vehicle speed signal using a configurable low pass filter to smooth out noise and sudden changes.
Vehicle Speed Error Checking	Performs error checking on the input speed signals such as range checks, comparison between different speed sources, etc. and sets diagnostic flags based on the checks.

4.28.3. Ports

	Id	Direction	Data Type	Dimensions	Unit	Description	Keywords
1	Ts	Incoming	single	[1]	s		Ts
2	WhlAgrV	Incoming	single	[4]	rpm	Expected signal: Wheel angular velocity (FL,FR,RL,RR) If signal is NA: mandatory.	Wheel Angular Velocity
3	WhlAgrVVld	Incoming	boolean	[4]	inherit	Expected signal: Wheel angular velocity validity If signal is NA: mandatory. [True True True True] Must be synch with the actual source	Wheel Angular Velocity Valid
4	ExtVehLgtSpd	Incoming	single	[1]	km/h	Expected signal: External vehicle longitudinal speed. IF available If signal is NA: None. Can be grounded	External Vehicle Longitudinal Speed
5	ExtVehLgtSpdVld	Incoming	boolean	[1]	inherit	Expected signal: External vehicle longitudinal speed validity. IF available If signal is NA: False if grounded	External Vehicle Longitudinal Speed Valid
6	SpdprocAxleSpd	Outgoing	single	[2]	rpm		Spdproc Axle Speed
7	SpdprocAxleSpdVld	Outgoing	boolean	[2]			Spdproc Axle Speed Valid
8	SpdprocVehSpdSign	Outgoing	single	[1]	km/h		Spdproc Vehicle Speed Sign
9	SpdprocVehSpdAbs	Outgoing	single	[1]	km/h		Spdproc Vehicle Speed Abs
10	SpdprocVehSpdSignFild	Outgoing	single	[1]	km/h		Spdproc Vehicle Speed Sign Filtered
11	SpdprocVehSpdVld	Outgoing	boolean	[1]	inherit		Spdproc Vehicle Speed Valid
12	SpdprocVehStndslFlg	Outgoing	boolean	[1]	inherit		Spdproc Vehicle Standstill Flag
13	SpdprocArbdSrc	Outgoing	uint8	[1]	inherit		Spdproc Arbitrated Source
14	SpdprocErrCod	Outgoing	uint8	[1]	inherit		Spdproc Error Code
15	SpdprocMotSpdPrcsd	Outgoing	single	[4]	%		Spdproc Motor Speed Processed
16	SpdprocMotBasdVehSpd	Outgoing	single	[1]	km/h		Spdproc Motor Based Vehicle Speed
17	SpdprocMotBasdVehSpdErr	Outgoing	boolean	[1]	inherit		Spdproc Motor Based Vehicle Speed Error
18	SpdprocDiagc	Outgoing	Bus: SpdprocDiagc	[-1]	inherit		Spdproc Diagnostic

4.28.4. Parameters

	Id	Data Type	Dimensions	Range	Unit	Description	Keywords
1	SpdprocErrScrVldDifTolr	single	[1,1]	Min: 0, Max:	km/h	error check: the tolerance for value difference between speed sources - motors and external source	Spdproc Error Screen Valid Difference Tolerance
2	SpdprocStndslHiLim	single	[1,1]	Min: 0.5, Max: 100	km/h	veh. in standstill If Speed<this value	Spdproc Standstill High Limit
3	SpdprocFilTau	single	[1,1]	Min: 0, Max: 1	sec	Speed filtering time constant, lower -> faster response, 0 - disable	Spdproc Filter Tau
4	SpdprocSpdZeroTolr	single	[1,1]	Min: 0, Max:	km/h	zeroing speed value if absolute speed value is less than this threshold	Spdproc Speed Zero Tolerance
5	SpdprocMaxSpdErr	uint16	[1,1]	Min: 0, Max: 65535	km/h	error check: vehicle top speed	Spdproc Maximum Speed Error
6	SpdprocSrcArbr	uint8	[1,1]	Min: 0, Max: 2		veh speed source arbitration: 0 - Arbitrate, 1 - take External only, 2 - take Wheel source only	Spdproc Source Arbitrator
7	SpdprocMotSpdMax	uint16	[1,1]	Min: 1, Max: 65535	rpm	motor max speed for percentage motor speed signal	Spdproc Motor Speed Maximum
8	SpdprocDifTiTolr	uint8	[1,1]	Min: 0, Max: 50		error check: time tolerance for value difference between different 2 speed sources, 0:10 maps to [0:0.05:0.5] sec, in number of samples	Spdproc Difference Time Tolerance

4.28.5. Configuration Guide

The VehSpdProcg component arbitrates between an external vehicle speed input and an internal calculation of vehicle speed based on wheel speeds, considering the validity of the external input. The VehSpdProcg component shall be properly configured to take intended speed inputs and correctly perform an arbitration.

4.28.5.1. Step 1 - Configure Vehicle Speed Sources

Set the vehicle speed source arbitration method using SpdprocSrcArbr as follows: 0 - Arbitrate, 1 - take External only, 2 - take Wheel source only.

Configure the maximum allowable speed error using SpdprocMaxSpdErr in km/h.

Set the maximum motor speed threshold with SpdprocMotSpdMax in rpm.

4.28.5.2. Step 2 - Configure Vehicle Speed Filter

Adjust the speed filtering time constant using SpdprocFilTau as necessary.

4.28.5.3. Step 3 - Configure Vehicle Standstill Flag conditions

Define the vehicle speed dead-band using SpdprocSpdZeroTolr (Speed under which vehicle speed is considered zero).

Configure the vehicle standstill flag condition with SpdprocStndslHiLim threshold, in km/h.

4.28.5.4. Step 4 - Configure Vehicle Speed Comparison Monitor

Set the threshold for speed comparison warning using SpdprocErrScrVldDifTolr. Note that the component provides a warning flag in SpdProcDiagc diagnostics bus when speed mismatch is detected, but continues to provide the arbitrated speed value.

Define time tolerance for speed comparison warning using SpdprocDifTiTolr.