IP Library Granted Patent US 12,545,235
Granted Patent B2
US 12,545,235 · App. 18/678,052 · Granted Feb 10, 2026

Systems and methods for adjusting wheel rotational speed to reduce passenger motion sickness

Inventors: Hiroshi Yasuda (San Carlos, CA); Andrea Michelle Rios Lazcano (Brussels, BE)
Assignees: Toyota Research Institute, Inc.; Toyota Jidosha Kabushiki Kaisha
B60W30/025B60W2520/105B60W2720/16
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Quick Facts
Patent No.
US 12,545,235
App. No.
18/678,052
Granted
Feb 10, 2026
Kind
B2
Abstract

Systems, methods, and other embodiments described herein relate to reducing passenger motion sickness resulting from a pitch change of a vehicle as a navigated road changes slope. In one embodiment, a method includes detecting a slope in a road in front of a vehicle and detecting a motion sickness state of a passenger of the vehicle. The method includes, adjusting, based on the motion sickness state of the passenger, a pitch angle of the vehicle to offset a slope angle of the road. The pitch angle is adjusted by independently adjusting a rotational speed of different wheels of the vehicle to generate a difference between a front wheel rotational speed of the vehicle and a rear wheel rotational speed of the vehicle.

Claims (71)

1 . A system, comprising:

a processor; and

a memory storing machine-readable instructions that, when executed by the processor, cause the processor to:

detect a slope in a road in front of a vehicle;

detect a motion sickness state of a passenger of the vehicle; and

adjust, based on the motion sickness state of the passenger, a pitch angle of the vehicle to offset a slope angle of the road by independently adjusting a rotational speed of different wheels of the vehicle to generate a difference between a front wheel rotational speed of the vehicle and a rear wheel rotational speed of the vehicle.

2 . The system of claim 1 , wherein the machine-readable instruction that, when executed by the processor, causes the processor to detect the slope in the road comprises a machine-readable instruction that, when executed by the processor, causes the processor to detect the slope in the road based on at least one of:

vehicle sensor data;

environment sensor data;

map data; or

crowd-sourced sensor data.

3 . The system of claim 1 , wherein the machine-readable instruction that, when executed by the processor, causes the processor to detect the motion sickness state of the passenger comprises a machine-readable instruction that, when executed by the processor, causes the processor to detect the motion sickness state of the passenger based on at least one of:

real-time passenger sensor data;

real-time vehicle sensor data; or

historical passenger profile data.

4 . The system of claim 1 , wherein the machine-readable instruction that, when executed by the processor, causes the processor to adjust the pitch angle of the vehicle comprises a machine-readable instruction that, when executed by the processor, causes the processor to adjust the pitch angle of the vehicle based on at least one of:

a value of the slope angle; or

a vehicle characteristic.

5 . The system of claim 1 , wherein the machine-readable instruction that, when executed by the processor, causes the processor to adjust the rotational speed of different wheels of the vehicle to generate the difference between the front wheel rotational speed of the vehicle and the rear wheel rotational speed of the vehicle comprises machine-readable instructions that, when executed by the processor, cause the processor to:

adjust a rotational speed of front wheels of the vehicle;

adjust a rotational speed of rear wheels of the vehicle; or

adjust the rotational speed of the front wheels of the vehicle and the rotational speed of the rear wheels of the vehicle, wherein:

the rotational speeds of the front wheels are the same; and

the rotational speed of the rear wheels are the same.

6 . The system of claim 1 , wherein the machine-readable instruction that, when executed by the processor, causes the processor to adjust the rotational speed of different wheels of the vehicle comprises machine-readable instructions that, when executed by the processor, cause the processor to adjust the rotational speed of different wheels based on a degree of motion sickness of the passenger.

7 . The system of claim 1 , wherein the machine-readable instruction that, when executed by the processor, causes the processor to adjust the rotational speed of different wheels of the vehicle to generate the difference between the front wheel rotational speed of the vehicle and the rear wheel rotational speed of the vehicle comprises machine-readable instructions that, when executed by the processor, cause the processor to:

adjust the rotational speed of the different wheels so the rotational speed of front wheels is greater than the rotational speed of rear wheels when the slope angle is positive; and

adjust the rotational speed of the different wheels so the rotational speed of the front wheels is less than the rotational speed of the rear wheels when the slope angle is negative.

8 . The system of claim 1 , wherein the machine-readable instructions further comprise a machine-readable instruction that, when executed by the processor, causes the processor to align the front wheel rotational speed and the rear wheel rotational speed responsive to the slope angle of the road being less than a threshold amount.

9 . The system of claim 1 , wherein the machine-readable instructions further comprise a machine-readable instruction that, when executed by the processor, causes the processor to maintain the difference between the front wheel rotational speed and the rear wheel rotational speed responsive to a driver-based acceleration input.

10 . The system of claim 1 , wherein the machine-readable instruction that, when executed by the processor, causes the processor to adjust the rotational speed of different wheels of the vehicle to generate the difference between the front wheel rotational speed of the vehicle and the rear wheel rotational speed of the vehicle comprises machine-readable instructions that, when executed by the processor, cause the processor to:

determine a target pitch adjustment for the vehicle based on the slope angle;

determine a target difference between the front wheel rotational speed and the rear wheel rotational speed based on the target pitch adjustment; and

set the rotational speed of the front wheels and the rotational speed of the rear wheels based on the target difference.

11 . A non-transitory machine-readable medium comprising instructions that, when executed by a processor, cause the processor to:

detect a slope in a road in front of a vehicle;

detect a motion sickness state of a passenger of the vehicle; and

adjust, based on the motion sickness state of the passenger, a pitch angle of the vehicle to offset a slope angle of the road by independently adjusting a rotational speed of different wheels of the vehicle to generate a difference between a front wheel rotational speed of the vehicle and a rear wheel rotational speed of the vehicle.

12 . The non-transitory machine-readable medium of claim 11 , wherein the instruction that, when executed by the processor, causes the processor to detect the slope in the road comprises an instruction that, when executed by the processor, causes the processor to detect the slope in the road based on at least one of:

vehicle sensor data;

environment sensor data;

map data; or

crowd-sourced sensor data.

13 . The non-transitory machine-readable medium of claim 11 , wherein the instruction that, when executed by the processor, causes the processor to adjust the pitch angle of the vehicle comprises an instruction that, when executed by the processor, causes the processor to adjust the pitch angle of the vehicle based on at least one of:

a value of the slope angle; or

a vehicle characteristic.

14 . The non-transitory machine-readable medium of claim 11 , wherein the instruction that, when executed by the processor, causes the processor to adjust the rotational speed of different wheels of the vehicle to generate the difference between the front wheel rotational speed of the vehicle and the rear wheel rotational speed of the vehicle comprises instructions that, when executed by the processor, cause the processor to:

adjust the rotational speed of the different wheels so the rotational speed of front wheels is greater than the rotational speed of rear wheels when the slope angle is positive; and

adjust the rotational speed of the different wheels so the rotational speed of the front wheels is less than the rotational speed of the rear wheels when the slope angle is negative.

15 . The non-transitory machine-readable medium of claim 11 , wherein the instruction that, when executed by the processor, causes the processor to adjust the rotational speed of different wheels of the vehicle to generate the difference between the front wheel rotational speed of the vehicle and the rear wheel rotational speed of the vehicle comprises instructions that, when executed by the processor, cause the processor to:

determine a target pitch adjustment for the vehicle based on the slope angle;

determine a target difference between the front wheel rotational speed and the rear wheel rotational speed based on the target pitch adjustment; and

set the rotational speed of the front wheels and the rotational speed of the rear wheels based on the target difference.

16 . A method, comprising:

detecting a slope in a road in front of a vehicle;

detecting a motion sickness state of a passenger of the vehicle; and

adjusting, based on the motion sickness state of the passenger, a pitch angle of the vehicle to offset a slope angle of the road by independently adjusting a rotational speed of different wheels of the vehicle to generate a difference between a front wheel rotational speed of the vehicle and a rear wheel rotational speed of the vehicle.

17 . The method of claim 16 , wherein detecting the motion sickness state of the passenger comprises detecting the motion sickness state of the passenger based on at least one of:

real-time passenger sensor data;

real-time vehicle sensor data; or

historical passenger profile data.

18 . The method of claim 16 , wherein adjusting the pitch angle of the vehicle comprises adjusting the pitch angle of the vehicle based on at least one of:

a value of the slope angle; or

a vehicle characteristic.

19 . The method of claim 16 , wherein adjusting the rotational speed of different wheels of the vehicle to generate the difference between the front wheel rotational speed of the vehicle and the rear wheel rotational speed of the vehicle comprises:

adjusting the rotational speed of the different wheels so the rotational speed of front wheels is greater than the rotational speed of rear wheels when the slope angle is positive; and

adjusting the rotational speed of the different wheels so the rotational speed of the front wheels is less than the rotational speed of the rear wheels when the slope angle is negative.

20 . The method of claim 16 , wherein adjusting the rotational speed of different wheels of the vehicle to generate the difference between the front wheel rotational speed of the vehicle and the rear wheel rotational speed of the vehicle comprises:

determining a target pitch adjustment for the vehicle based on the slope angle;

determining a target difference between the front wheel rotational speed and the rear wheel rotational speed based on the target pitch adjustment; and

setting the rotational speed of the front wheels and the rotational speed of the rear wheels based on the target difference.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 8, 2026
From: TOYOTA RESEARCH INSTITUTE, INC.
To: TOYOTA JIDOSHA KABUSHIKI KAISHA
Reel/Frame 074884/0933 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 5, 2024
From: YASUDA, HIROSHI; RIOS LAZCANO, ANDREA MICHELLE
To: TOYOTA RESEARCH INSTITUTE, INC.; TOYOTA JIDOSHA KABUSHIKI KAISHA
Reel/Frame 067627/0489 →
Continuity (1)
Related Publication 20250368185A1 · Dec 4, 2025
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