# US 11,897,340 B2 · Systems and methods for free wheel towing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,897,340 B2 - Document ID: US11897340B2 - Status: Granted - Kind: B2 - Application number: 17/318,683 - Filed: 2021-05-12 - Published: 2022-11-17 - Granted: 2024-02-13 - Earliest claimed: 2021-05-12 - Assignees: Rivian IP Holdings, LLC - Applicants: Rivian IP Holdings, LLC - Inventors: Rahul Madineni - Web page: https://patentgrep.com/patent/US11897340B2 ## CPC - B60L 15/2018: {for braking on a slope} - H02P 6/08: Arrangements for controlling the speed or torque of a single motor (H02P6/10, H02P6/28 take precedence) - B60W 10/08: including control of electric propulsion units, e.g. motors or generators - B60W 10/18: including control of braking systems - B60W 30/02: Control of vehicle driving stability - B60W 30/18118: {Hill holding} - H02P 27/06: using DC to AC converters or inverters (H02P27/05 takes precedence) - B60L 2240/642: Slope of road - B60W 2530/203: Presence of trailer - B60W 2552/15: Road slope, i.e. the inclination of a road segment in the longitudinal direction - B60W 2710/081: Speed - B60W 2710/083: Torque - B60W 2710/18: Braking system - Y02T 10/72: Electric energy management in electromobility - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract Various disclosed embodiments include illustrative drive unit controllers, drive units, and vehicles. In an illustrative embodiment, a drive unit controller includes a processor having computer-readable media configured to store computer-executable instructions configured to cause the processor to receive free-wheel tow mode activation information, activate a hold mode based on the received free-wheel tow mode activation information, generate a zero-speed command in response to the hold mode being activated, and send the generated zero-speed command to a stabilizing system of the associated vehicle. ## Claims ### Claim 1 A controller comprising: a processor having computer-readable media configured to store computer-executable instructions configured to cause the processor to: receive free-wheel tow mode activation information of an associated vehicle; activate a hold mode based on the received free-wheel tow mode activation information; generate a zero-speed command in response to the hold mode being activated; send the generated zero-speed command to a stabilizing system of the associated vehicle; compare the generated zero-speed command to a threshold value; and deactivate the hold mode in response to the generated zero-speed command being greater than the threshold value such that the processor ceases to generate the zero-speed command until the free-wheel tow mode is deselected by a user. ### Claim 2 (depends on 1) The controller of claim 1, wherein the computer-executable instructions are further configured to cause the processor to: receive slope grade information; and generate an initial zero-speed command in response to the received slope grade information. ### Claim 3 (depends on 1) The controller of claim 1, wherein the computer-executable instructions are further configured to cause the processor to adjust the zero-speed command in response to motor position information. ### Claim 4 (depends on 3) The controller of claim 3, wherein the zero-speed command includes a motor speed control signal. ### Claim 5 (depends on 3) The controller of claim 3, wherein the stabilizing system includes an inverter and an electric motor of a drive unit, the inverter being configured to receive the zero-speed command and direct electric motor operation in response thereto. ### Claim 6 (depends on 3) The controller of claim 3, wherein the zero-speed command includes a torque command. ### Claim 7 (depends on 6) The controller of claim 6, wherein the stabilizing system includes an inverter and an electric motor of a drive unit, the inverter being configured to receive the torque command and direct electric motor operation in response thereto. ### Claim 8 (depends on 1) The controller of claim 1, wherein the zero-speed command includes a brake command. ### Claim 9 (depends on 8) The controller of claim 8, wherein the stabilizing system includes a brake system configured to receive the brake command and apply associated braking action in response thereto. ### Claim 10 (depends on 1) The controller of claim 1, wherein the associated vehicle is configured as a highway vehicle. ### Claim 11 (depends on 1) The controller of claim 1, wherein, in response to receiving the free-wheel tow mode activation information, the processor is configured to store computer readable instructions configured to cause the processor to mechanically decouple at least one wheel of the associated vehicle from at least one drive unit of the associated vehicle. ### Claim 12 A drive unit comprising: an electric motor; an encoder configured to generate motor speed information of the electric motor; an inverter configured to control operation of the electric motor; and a controller including: a processor having computer-readable media configured to store computer-executable instructions configured to cause the processor to: receive free-wheel tow mode activation information of an associated vehicle; activate a hold mode based on the received free-wheel tow mode activation information; generate a zero-speed command in response to the hold mode being activated; send the generated zero-speed command to the inverter; compare the generated zero-speed command to a threshold value; and deactivate the hold mode in response to the generated zero-speed command being greater than the threshold value such that the processor ceases to generate the zero-speed command until the free-wheel tow mode is deselected by a user. ### Claim 13 (depends on 12) The drive unit of claim 12, wherein the computer-executable instructions are further configured to cause the processor to: receive slope grade information; and generate an initial zero-speed command in response to the received slope grade information. ### Claim 14 (depends on 12) The drive unit of claim 12, wherein the computer-executable instructions are further configured to cause the processor to generate the zero-speed command in response to the motor speed information. ### Claim 15 (depends on 14) The drive unit of claim 14, wherein the zero-speed command includes a motor speed control signal. ### Claim 16 (depends on 14) The drive unit of claim 14, wherein the zero-speed command includes a torque command. ### Claim 17 A vehicle comprising: a human-machine interface unit configured to generate a tow mode activation signal; and a drive unit including: an electric motor; an encoder configured to generate motor speed information of the electric motor; and an inverter configured to control operation of the electric motor; and a controller including a processor having computer-readable media configured to store computer-executable instructions configured to cause the processor to: receive the generated tow mode activation signal from the human-machine interface unit; activate a hold mode in response to the received tow mode activation signal; generate a zero-speed command in response to the hold mode being activated; send the generated zero-speed command to the inverter; compare the generated zero-speed command to a threshold value; and deactivate the hold mode in response to the generated zero-speed command being greater than the threshold value such that the processor ceases to generate the zero-speed command until the free-wheel tow mode is deselected by a user. ### Claim 18 (depends on 17) The vehicle of claim 17, further comprising: a vehicle status unit configured to generate slope grade information, wherein the computer-executable instructions are further configured to cause the processor to: receive the generated slope grade information; and generate an initial zero-speed command in response to the received slope grade information. ### Claim 19 (depends on 17) The vehicle of claim 17, wherein the zero speed command includes a motor speed command. ### Claim 20 (depends on 17) The drive unit of claim 17, wherein the zero speed command includes a torque command.