4.30. Wheel Torque Limit Manager - WhlTqLim

• Overview

• Functions

• Ports

• Parameters

• Calibration

Id	WhlTqLim
Version	0.1.2.0
Title	Wheel Torque Limit Manager
System	Drivetrain
Document Type	Application Software Component Specification Preview

4.30.1. Overview

The Wheel Torque Limit (WhlTqLim) component is responsible for saturating the wheel torque demand for each wheel based on various input limit sources. Limits take into account driver demand, traction control, inverter, and external wheel torque requests to determine the final (saturated) wheel torque demand.

4.30.2. Functions

Title	Description
Calculate Wheel Torque Demand	Calculates the wheel torque demand for each wheel based on driver demand, traction control limits, inverter limits, and external wheel torque requests. Applies limits and selects the appropriate torque demand source.
Calculate Wheel Torque Limits	Determines the maximum drive and regen torque limits for each wheel based on inverter limits and traction control limits. Outputs the torque limits and their corresponding sources.

4.30.3. Ports

	Id	Direction	Data Type	Dimensions	Unit	Description	Keywords
1	TcsWhlDrvTqLim	Incoming	single	[4]	N*m	Expected signal: TCS wheel torque demand (modulating torque - FL, FR, RL, RR) If signal si NA: [0 0 0 0]	Tcs Wheel Drive Torque Limit
2	WhlTqDmdIn	Incoming	single	[4]	N*m	Expected signal: Wheel torque demand (FL, FR, RL, RR) If signal si NA: mandatory	Wheel Torque Demand In
3	VehTqLimSrc	Incoming	Enum: CmndrvTqSrc	[1]	inherit	Expected signal: Limiting wheel torque at vehicle level If signal si NA: mandatory. Any CmndrvTqSrc source. See enum for full list	Vehicle Torque Limit Source
4	InvctlWhlDrvTqLim	Incoming	single	[4]	N*m	Expected signal: Limiting regen torque from inverter (FL, FR, RL, RR) If signal si NA: mandatory. Any reasonable high toque	Invctl Wheel Drive Torque Limit
5	InvctlWhlRgnTqLim	Incoming	single	[4]	N*m	Expected signal: Limiting drive torque from inverter (FL, FR, RL, RR) If signal si NA: mandatory. Any reasonable regen toque	Invctl Wheel Regeneration Torque Limit
6	InvctlWhlTqLimRsn	Incoming	Enum: CmndrvTqSrc	[4]	inherit	Expected signal: Limiting wheel torque. Same as WhltqLimRsn If signal si NA: mandatory. Any CmndrvTqSrc source. See enum for full list	Invctl Wheel Torque Limit Reason
7	ExtWhlTqReq	Incoming	single	[4]	N*m	Expected signal: External wheel torque demand (FL, FR, RL, RR) If signal si NA: [0 0 0 0]	External Wheel Torque Request
8	ExtWhlTqReqVld	Incoming	boolean	[4]	inherit	Expected signal: External wheel torque demand validity If signal si NA: [true true true true]	External Wheel Torque Request Valid
9	WhlTqProhtd	Incoming	boolean	[1]	inherit	Expected signal: External wheel torque demand Prohibited If signal si NA: [false false false false]	Wheel Torque Prohibited
10	WhlTqDmd	Outgoing	single	[4]	N*m		Wheel Torque Demand
11	WhlTqDmdSrc	Outgoing	Enum: CmndrvTqSrc	[4]	inherit		Wheel Torque Demand Source
12	WhlTqDmdPreTcs	Outgoing	single	[4]	N*m		Wheel Torque Demand Pre Tcs
13	WhlTqLimPreTcs	Outgoing	single	[8]	N*m		Wheel Torque Limit Pre Tcs
14	WhlTqDrvMax	Outgoing	single	[4]	N*m		Wheel Torque Drive Maximum
15	WhlTqRgnMax	Outgoing	single	[4]	N*m		Wheel Torque Regeneration Maximum
16	WhltqlimOutFrntLe	Outgoing	Bus: CAN_WhltqlimOutFrntLe_t	[-1]	inherit		Whltqlim Output Front Left
17	WhltqlimOutFrntRi	Outgoing	Bus: CAN_WhltqlimOutFrntRi_t	[-1]	inherit		Whltqlim Output Front Right
18	WhltqlimOutReLe	Outgoing	Bus: CAN_WhltqlimOutReLe_t	[-1]	inherit		Whltqlim Output Rear Left
19	WhltqlimOutReRi	Outgoing	Bus: CAN_WhltqlimOutReRi_t	[-1]	inherit		Whltqlim Output Rear Right
20	WhltqlimOutFrntLe_send	Outgoing	boolean	[1]	inherit
21	WhltqlimOutFrntRi_send	Outgoing	boolean	[1]	inherit
22	WhltqlimOutReLe_send	Outgoing	boolean	[1]	inherit
23	WhltqlimOutReRi_send	Outgoing	boolean	[1]	inherit
24	YawMomPostLimn	Outgoing	single	[1]	N*m		Yaw Moment Post Limitation
25	TqReqPostLimn	Outgoing	single	[1]	N*m		Torque Request Post Limitation

4.30.4. Parameters

	Id	Data Type	Dimensions	Range	Unit	Description	Keywords
1	TqctlWhlDrvTqFrntLim	single	[1,1]	Min: , Max:		Front wheel drive torque limit	Tqctl Wheel Drive Torque Front Limit
2	TqctlWhlDrvTqReLim	single	[1,1]	Min: , Max:		Rear wheel drive torque limit	Tqctl Wheel Drive Torque Rear Limit
3	TqctlWhlRgnTqFrntLim	single	[1,1]	Min: , Max:		Front wheel regen torque limit	Tqctl Wheel Regeneration Torque Front Limit
4	TqctlWhlRgnTqReLim	single	[1,1]	Min: , Max:		Rear wheel regen torque limit	Tqctl Wheel Regeneration Torque Rear Limit
5	TqctlExtWhlTqEnad	boolean	[1,1]	Min: , Max:		Enable External wheel torque	Tqctl External Wheel Torque Enabled

4.30.5. Calibration

WhlTqLim must be set up according to the specifications of the overall vehicle system.

4.30.5.1. Step 1 - Set per-wheel limits

Set TqctlWhlDrvTqFrntLim and TqctlWhlDrvTqReLim as the wheel torque limit in traction scenario.
Similarly, set TqctlWhlDrvTqReLim and TqctlWhlRgnTqReLim for regen scenario.
Traction limit must be positive number, whereas, Regen must be negative.

These are the two limits that will be considered as static ones. Further limitations are passed as inputs to the block.

4.30.5.2. Step 2 - Selection of torque demand input

There are two possible torque demand inputs. The primary torque demand from Inport #2: WhlTqDmdIn and the external torque demand from Inport #7: ExtWhlTqReq.

Set TqctlExtWhlTqEnad to true to enable torque demand override. In this case the software component takes wheel torque demand coming from an external source, e.g. electronic braking system.
The drivetrain torque demand is then overridden by the external source from Inport #7: ExtWhlTqReq, as long as the validity flag from Inport #8: ExtWhlTqReqVld is true. Otherwise, the torque demand is taken from Inport #2: WhlTqDmdIn as if TqctlExtWhlTqEnad was set to false.

Additionally, if Inport #9: WhlTqProhtd is true, the torque demand will be taken from Inport #2: WhlTqDmdIn regardless of TqctlExtWhlTqEnad.

4.30.5.3. Step 3 - Definition of vehicle parameters for cornering characteristics

Provide vehicle’s rear track width VehprmVehTrkWidthRe and VehprmTyrEfcRollgRdRe in order to get an approximation of the target yaw moment after wheel torque limits are applied.

4.30.5.4. Step 4 - Enable sending of the debug CAN message

Set TqctlSndWhltqlimOut to true if debug CAN messages are desired. false otherwise.

4.30.5.5. Notes

None