4.4. Demanded Torque Allocation Controller - CtlAllcn

• Overview

• Functions

• Ports

• Parameters

• Calibration

Id	CtlAllcn
Version	0.4.0.0
Title	Demanded Torque Allocation Controller
System	Drivetrain
Document Type	Application Software Component Specification Preview

4.4.1. Overview

The Control Allocation component distribes the vehicle torque demand to the individual wheels based on various factors such as torque vectoring control (TVC) status, wheelvertical forces, and torque bias strategies taking into consideration individual wheel torque limits provided as an input.

4.4.2. Functions

Title	Description
Allocate Demanded Torque To Wheels	Distributes the demanded vehicle driving torque to the front left, front right, rear left and rear right wheels based on the selected allocation variant, wheel torque limits and TVC yaw moment request.
Calculate Vehicle Driving Torque Limits	Determines the maximum and minimum possible vehicle driving torque based on the individual wheel torque limits.

4.4.3. Ports

	Id	Direction	Data Type	Dimensions	Unit	Description	Keywords
1	Ts	Incoming	single	[1]	s		Ts
2	TvcRefYawMom	Incoming	single	[1]	N*m	Expected signal: Torque vectoring reference yaw moment. If signal si NA: grounded	Tvc Reference Yaw Moment
3	VehDrvgTqDmd	Incoming	single	[1]	N*m	Expected signal: Vehicle torque request If signal si NA: mandatory	Vehicle Driving Torque Demand
4	WhlTqLim	Incoming	single	[8]	N*m	Expected signal: Limiting wheel torque If signal si NA: mandatory. Any reasonable high enough value	Wheel Torque Limit
5	WhlVertF	Incoming	single	[4]	N	Expected signal: Vehicle vertical load possibly coming from a state estimator (FL,FR,RL,RR) If signal si NA: mandatory.	Wheel Vertical Force
6	TvcEnadFlg	Incoming	boolean	[1]	inherit	Expected signal: Torque vectoring enabled flag If signal si NA: mandatory. False if TVC not present	Tvc Enabled Flag
7	CtlallcnWhlTqDmd	Outgoing	single	[4]	N*m		Ctlallcn Wheel Torque Demand
8	CtlallcnYawMomMaxAtTqDmd	Outgoing	single	[1]	N*m		Ctlallcn Yaw Moment Maximum At Torque Demand
9	CtlallcnYawMomMinAtTqDmd	Outgoing	single	[1]	N*m		Ctlallcn Yaw Moment Minimum At Torque Demand
10	CtlallcnVehDrvTqMax	Outgoing	single	[1]	N*m		Ctlallcn Vehicle Drive Torque Maximum
11	CtlallcnVehDrvTqMin	Outgoing	single	[1]	N*m		Ctlallcn Vehicle Drive Torque Minimum
12	CtlAllcnOut1	Outgoing	Bus: CAN_CtlAllcnOut1_t	[-1]	inherit		Control Allocation Output1
13	CtlAllcnOut1_send	Outgoing	boolean	[1]	inherit
14	CtlAllcnOut2	Outgoing	Bus: CAN_CtlAllcnOut2_t	[-1]	inherit		Control Allocation Output2
15	CtlAllcnOut2_send	Outgoing	boolean	[1]	inherit

4.4.4. Parameters

	Id	Data Type	Dimensions	Range	Unit	Description	Keywords
1	CtlallcnTqBiasLutBrkPnt	single	[26,1]	Min: -10000, Max: 10000	N*m	Vehicle torque breakpoints for Variant 3 Lookup tables	Ctlallcn Torque Bias Lut Brake Point
2	CtlallcnTqBiasLutVal	single	[26,2]	Min: 0, Max: 1		Torque bias values for Variant 3 Lookup tables - 0 (full front) to 1 (full rear)	Ctlallcn Torque Bias Lut Value
3	CtlallcnConTqDibtnTrac	single	[1,1]	Min: 0, Max: 1		Fixed torque distribution in traction (used by Fixed ratio variant) - 0 (full front) to 1 (full rear)	Ctlallcn Constant Torque Distribution Traction
4	CtlallcnCanDiag	boolean	[1,1]	Min: 0, Max: 1		Send Ctlallcn CAN Diagnostics message	Ctlallcn Can Diagnosis
5	CtlallcnTqBiasVrnt3FilFrq	single	[1,1]	Min: 0, Max: 50	Hz	Filtering frequency of torque bias in variant 3 - LUT mode	Ctlallcn Torque Bias Variant3 Filter Frequency
6	CtlallcnTqBiasVrnt2FilFrq	single	[1,1]	Min: 0, Max: 50	Hz	Filtering frequency of torque bias in variant 2 - Fz mode	Ctlallcn Torque Bias Variant2 Filter Frequency
7	CtlallcnTqBiasVrnt1FilFrq	single	[1,1]	Min: 0, Max: 50	Hz	Filtering frequency of torque bias in variant 1 - Fixed mode	Ctlallcn Torque Bias Variant1 Filter Frequency
8	CtlallcnConTqDibtnRgn	single	[1,1]	Min: 0, Max: 1		Fixed torque distribution in regen (used by Fixed ratio variant) - 0 (full front) to 1 (full rear)	Ctlallcn Constant Torque Distribution Regeneration
9	CtlallcnTqBiasCorrnRgnEnad	boolean	[1,1]	Min: 0, Max: 1		Enable torque bias correction in case of saturation in regen	Ctlallcn Torque Bias Correction Regeneration Enabled
10	CtlallcnTqBiasCorrnTracEnad	boolean	[1,1]	Min: 0, Max: 1		Enable torque bias correction in case of saturation in traction	Ctlallcn Torque Bias Correction Traction Enabled
11	CtlallcnWhlDrvTqLimCorrnRgnEnad	boolean	[1,1]	Min: 0, Max: 1		Wheel torque limit recalculation based on bias in regen	Ctlallcn Wheel Drive Torque Limit Correction Regeneration Enabled
12	CtlallcnWhlDrvTqLimCorrnTracEnad	boolean	[1,1]	Min: 0, Max: 1		Wheel torque limit recalculation based on bias in traction	Ctlallcn Wheel Drive Torque Limit Correction Traction Enabled
13	CtlallcnVrntTvcOff	single	[1,1]	Min: 0, Max: 3		Control allocation variant selector when TVC is off: 1 - Fixed Ratio, 2 - Fz Proportional, 3 - LUT	Ctlallcn Variant Tvc Off
14	CtlallcnVrntTvcOn	single	[1,1]	Min: 0, Max: 10		Control allocation variant selector when TVC is active: 1 - Fixed Ratio, 2 - Fz Proportional, 3 - LUT	Ctlallcn Variant Tvc On

4.4.5. Calibration

CtlAllc software component must be set up in agreement with vehicle powertrain architecture and desired torque allocation strategy.

4.4.5.1. Step 1 - Vehicle characteristics

Make sure the vehicle parameters match the real vehicle:
VehprmTyrEfcRollgRdFrnt Front tyre effective rolling radius
VehprmVehTrkWidthFrnt Front track width
VehprmTyrEfcRollgRdRe Rear tyre effective rolling radius
VehprmVehTrkWidthRe Rear track width

4.4.5.2. Step 2 - Selection of left-to-right torque allocation variant

Use CtlallcnVrntTvcOn to select Control Allocation behaviour when Torque Vectoring feature is active (if available). Possible strategies:
1 Fixed Ratio (fixed ratio expressed as rear-to-total torque bias)
2 Fz Proportional (torque bias proportional to vertical load on each axle)
3 LUT (user defined torque bias via a lookup table)

4.4.5.3. Sub step 2.1 - Fixed ratio

Provide CtlallcnConTqDibtnTrac (torque_rear/total_torque) in traction scenario. Value in the range [0,1]
Provide CtlallcnConTqDibtnRgn (torque_rear/total_torque) in regeneration scenario. Value in the range [0,1]

4.4.5.4. Sub step 2.2 - Fz Proportional

No adjustment required here, the torque bias is automatically calculated proportionally to the vertical load on each axle.

4.4.5.5. Sub step 2.3 - LUT definition

The lookup table is two-dimensional, with total vehicle torque demand and yaw moment as its two dimensions. Provide CtlallcnTqBiasLutBrkPnt to set the vehicle total torque demand breakpoints for the lookup table. Vector size [mx1].
Provide CtlallcnYawMomDmdLutBrkPnt to set the yaw moment breakpoints for the lookup table. Vector size [nx1].
Provide CtlallcnTqBiasLutVal to set the torque bias values of the lookup table. For each cell, any value between 0 (full front) to 1 (full rear) can be provided. Array size [mxn].

Please, make sure that the number of rows (m) and columns (n) of the two vector is consistent with the torque bias array (mxn).

4.4.5.6. Step 3 - Enable torque bias correction in traction and regeneration scenarios

Set CtlallcnTqBiasCorrnTracEnad to true to enable torque bias correction in case of saturation in traction
Set CtlallcnTqBiasCorrnRgnEnad to true to enable torque bias correction in case of saturation in regereration

4.4.5.7. Step 4 - Enable/Disable recalculation of torque limits

Set CtlallcnWhlDrvTqLimCorrnTracEnad to true if recalculation of wheel torque limits based on bias in traction is needed
Set CtlallcnWhlDrvTqLimCorrnRgnEnad to true if recalculation of wheel torque limit recalculation based on bias in regen is needed

4.4.5.8. Step 5 - Enable/Disable debug CAN messages

Set CtlallcnCanDiag to true to broadcast CtlAllcnOut1 CAN message
Set CtlallcnCanDiag to true to broadcast CtlAllcnOut2 CAN message

4.4.5.9. Notes

None