# US 10,502,567 B2 · Roll angle estimation device and transport apparatus

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- Number: US 10,502,567 B2
- Document ID: US10502567B2
- Status: Granted
- Kind: B2
- Application number: 14/693,092
- Filed: 2015-04-22
- Published: 2015-10-29
- Granted: 2019-12-10
- Earliest claimed: 2014-04-25
- Assignees: Yamaha Hatsudoki Kabushiki Kaisha
- Applicants: Yamaha Hatsudoki Kabushiki Kaisha
- Inventors: Takahiro Fujii
- Web page: https://patentgrep.com/patent/US10502567B2

## CPC

- G01C 19/00: Gyroscopes; Turn-sensitive devices using vibrating masses; Turn-sensitive devices without moving masses; Measuring angular rate using gyroscopic effects
- B60W 40/11: Pitch movement
- B60W 40/112: Roll movement
- G01P 3/44: for measuring angular speed (G01P3/56 takes precedence)
- G01P 21/00: Testing or calibrating of apparatus or devices covered by the preceding groups
- B60W 2050/0013: {Optimal controllers}
- B60W 2050/002: {Integrating means}
- B60W 2050/0027: {Minimum/maximum value selectors}
- B60W 2050/005: {Sampling}
- B60W 2050/0056: {Low-pass filters}
- B60W 2050/0215: {Sensor drifts or sensor failures}
- B60W 2300/36: Cycles; Motorcycles; Scooters
- B60W 2420/905: the sensor being an xyz axis sensor
- B60W 2520/10: Longitudinal speed
- B60W 2520/105: Longitudinal acceleration
- B60W 2520/125: Lateral acceleration
- B60W 2520/16: Pitch
- B60W 2520/18: Roll
- B60W 2520/28: Wheel speed
- B60Y 2200/12: Motorcycles, Trikes; Quads; Scooters
- G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S)
- 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
- G01P: MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow A61B5/02, A61B8/06; monitoring speed or deceleration of electrically-propelled vehicles B60L3/00; vehicle lighting systems adapted to indicate speed B60Q1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying G01C; combined measuring devices for measuring two or more variables of movement G01C23/00; measuring velocity of sound G01H; measuring velocity of light G01J7/00; measuring direction or velocity of solid objects by reception or emission of radiowaves or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, G01S; measuring speed of nuclear radiation G01T; measuring acceleration of gravity G01V; {measuring or recording the speed of trains B61L23/00; speed indicators incorporated in motor vehicles B60K35/00; measuring frequency or phase G01R; traffic control G08G})
- B60Y: INDEXING SCHEME RELATING TO ASPECTS CROSS-CUTTING VEHICLE TECHNOLOGY

## Abstract

Arithmetic circuitry of a roll angle estimation device estimates a roll angle, a pitch angle a pitch angular velocity of the moving body and at least one offset error of angular velocity detectors and acceleration detectors. In a current estimation operation, the arithmetic circuitry estimates the roll angle, the pitch angle, and the pitch angular velocity and the at least one offset error, based on detection values of the angular velocity detectors, detection values of the acceleration detectors, a detection value by the velocity detector, estimated values of the roll angle, pitch angle, and pitch angular velocity from a previous estimation operation, and an estimated value of the at least offset error from the previous estimation operation.

## Claims

### Claim 1

A roll angle estimation device for estimating a roll angle of a moving body, comprising:
first and second angular velocity detectors which detect a roll angular velocity and a yaw angular velocity respectively around first and second axes and along two mutually different directions;
first, second, and third acceleration detectors which respectively detect first, second, and third accelerations along three mutually different directions;
a velocity detector which detects information concerning a moving velocity of the moving body in a direction of travel of the moving body; and
arithmetic circuitry configured to estimate
a current value of the roll angle of the moving body,
a current value of a pitch angle of the moving body,
a current value of a pitch angular velocity of the moving body, and
a current value of at least one offset error of the first and second angular velocity detectors and the first, second, and third acceleration detectors, based on:
detection values of the roll angular velocity and the yaw angular velocity by the first and second angular velocity detectors;
detection values of the first, second, and third accelerations by the first, second, and third acceleration detectors;
a detection value of the information by the velocity detector;
estimated previous values, from a previous estimation operation of the arithmetic circuitry, of the roll angle, the pitch angle, and the pitch angular velocity; and
an estimated previous value of the at least one offset error from the previous estimation operation of the arithmetic circuitry, wherein
the arithmetic circuitry estimates the current value of the pitch angle and the pitch angular velocity of the moving body by integrating
d
dt
⁡
[
θ
ω
p
]
=
[
ω
p
(
-
1
/
τ
)
*
ω
p
]
wherein
θ is the pitch angle,
ωp is the pitch angular velocity,
(l/τ) represents an exponential decay factor of the pitch angular velocity;
wherein the arithmetic circuitry comprises a Kalman filter which estimates the estimated current values for the roll angle, the pitch angle, the pitch angular velocity and the at least one offset error, and the Kalman filter is extended by application of an observation equation that calculates a value of vertical acceleration Gz, a value of lateral acceleration Gy and a value of rear-wheel speed vr based on at least the estimated value of the pitch angle θ and the estimated value of the pitch angular velocity ωp.

### Claim 2 (depends on 1)

The roll angle estimation device of claim 1, wherein the Kalman filter estimates the estimated current values for the roll angle, the pitch angle, the pitch angular velocity and the at least one offset error based on a relationship among:
the detection values by the first and second angular velocity detectors;
the detection values by the first, second, and third acceleration detectors;
the detection value of the information by the velocity detector;
the estimated previous values from the previous estimation operation of the roll angle, the pitch angle, and the pitch angular velocity; and
the estimated previous value of the at least one offset error from the previous estimation operation.

### Claim 3 (depends on 1)

The roll angle estimation device of claim 1, wherein the arithmetic circuitry estimates the estimated current value of the pitch angle based on an estimated previous value of the pitch angular velocity from the previous estimation operation, and estimates the estimated current value for the pitch angular velocity based on the estimated previous value of the pitch angular velocity from the previous estimation operation.

### Claim 4 (depends on 3)

The roll angle estimation device of claim 3, wherein the Kalman filter estimates the estimated current values for the roll angle, the pitch angle, the pitch angular velocity and the at least one offset error based on a relationship among:
the detection values by the first and second angular velocity detectors;
the detection values by the first, second, and third acceleration detectors;
the detection value of the information by the velocity detector;
the estimated previous values from the previous estimation operation of the roll angle, the pitch angle, and the pitch angular velocity; and
the estimated previous value of the at least one offset error from the previous estimation operation.

### Claim 5 (depends on 1)

The roll angle estimation device of claim 1, wherein the arithmetic circuitry estimates the current value for the pitch angle by integrating an estimated previous value of the pitch angular velocity over a period of time since the previous estimation operation.

### Claim 6 (depends on 5)

The roll angle estimation device of claim 5, wherein the Kalman filter estimates the estimated current values of the roll angle, the pitch angle, the pitch angular velocity and the at least one offset error based on a relationship among:
the detection values by the first and second angular velocity detectors;
the detection values by the first, second, and third acceleration detectors;
the detection value of the information by the velocity detector;
the estimated previous values from the previous estimation operation of the roll angle, the pitch angle, and the pitch angular velocity; and
the estimated previous value of the at least one offset error from the previous estimation operation.

### Claim 7 (depends on 2)

The roll angle estimation device of claim 2, wherein the Kalman filter comprises a saturation limiting circuit which,
when any of the estimated current values exceed an upper limit value of a predetermined range, sets the estimated current value, that exceeds the upper limit value, with the upper limit value, and
when any of the estimated current values is lower than a lower limit value of the predetermined range, sets the estimated current value, that is lower than the lower limit value, with the lower limit value.

### Claim 8 (depends on 7)

The roll angle estimation device of claim 7, wherein
one of the estimated current values exceeds the upper limit value of the predetermined range, so that the saturation limiting circuit sets the one estimated value with the upper limit value, and
the one estimated current value is one selected from the group consisting of the estimated current value of the roll angle, the estimated current value of the pitch angle, and an offset error of the pitch angular velocity.

### Claim 9 (depends on 7)

The roll angle estimation device of claim 7, wherein
one of the estimated current values is lower than the lower limit value of the predetermined range, so that the saturation limiting circuit sets the one estimated value with the lower limit value,
the one estimated current value is one selected from the group consisting of the estimated current value of the roll angle, the estimated current value of the pitch angle, and an offset error of the pitch angular velocity.

### Claim 10 (depends on 2)

The roll angle estimation device of claim 2, wherein the arithmetic circuitry includes low-pass filters that receive outputs from the first and second angular velocity detectors, the first, second, and third acceleration detectors, and the velocity detector, and
the arithmetic circuitry treats filtered outputs, that have been transmitted through the low-pass filters, as, respectively, the detection values of the first and second angular velocity detectors, the first, second, and third accelerations detector, and said velocity detector.

### Claim 11 (depends on 1)

The roll angle estimation device of claim 1, wherein,
the moving body includes a front wheel and a rear wheel;
said velocity detector includes a rear-wheel rotation speed detector which detects a rotation speed of the rear wheel as the information concerning the moving velocity of the moving body in the direction of travel of the moving body; and
the arithmetic circuitry further estimates the moving velocity of the moving body, and estimates the current value of the roll angle of the moving body, the current value of the at least one offset error, and a current value of the moving velocity of the moving body, based on:
the detection values of the roll angular velocity and the yaw angular velocity by the first and second angular velocity detectors;
the detection values of the first, second, and third accelerations by the first, second, and third acceleration detectors;
a detection value of the rotation speed by the rear-wheel rotation speed detector;
an estimated previous value of the roll angle from the previous estimation operation;
the estimated previous value of the at least one offset error from the previous estimation operation; and
an estimated previous value of the moving velocity from the previous estimation operation.

### Claim 12 (depends on 1)

The roll angle estimation device of claim 1, wherein,
the moving body includes a front wheel and a rear wheel;
said velocity detector includes
a front-wheel rotation speed detector which detects a rotation speed of the front wheel, and
a rear-wheel rotation speed arithmetic circuitry which estimates a rotation speed of the rear wheel from a detection value of the rotation speed of the front wheel by the front-wheel rotation speed detector as the information concerning the moving velocity of the moving body in the direction of travel of the moving body; and
the arithmetic circuitry further estimates the moving velocity of the moving body, and estimates the current value of the roll angle of the moving body, the current value of the at least one offset error, and a current value of the moving velocity of the moving body, based on:
the detection values of the first, second, and third accelerations by the first and second angular velocity detectors;
the detection values of the first, second, and third accelerations by the first, second, and third acceleration detectors;
an estimated value of the rotation speed of the rear wheel by the rear-wheel rotation speed arithmetic circuitry;
an estimated previous value of the roll angle from the previous estimation operation;
the estimated previous value of the at least one offset error from the previous estimation operation; and
an estimated previous value of the moving velocity from the previous estimation operation.

### Claim 13 (depends on 1)

A transport apparatus comprising:
the moving body of claim 1;
the roll angle estimation device of claim 1 which estimates the roll angle of the moving body; and
a processing device which controls the transport apparatus using the roll angle estimated by the roll angle estimation device.

### Claim 14 (depends on 1)

The roll angle estimation device of claim 1, wherein the arithmetic circuitry comprises a saturation limiting circuit which, for each respective estimated current value of the estimated current values, determines whether the respective estimated current value exceeds an upper limit value of a predetermined range, and sets the respective estimated current value with the upper limit value when the respective estimated current value exceeds the upper limit value.

### Claim 15 (depends on 1)

The roll angle estimation device of claim 1, wherein the arithmetic circuitry comprises a saturation limiting circuit which, for each respective estimated current value of the estimated current values, determines whether the respective estimated current value is lower than a lower limit value of a predetermined range, and sets the respective estimated current value with the lower limit value when the respective estimated current value is less than the lower limit value.

### Claim 16 (depends on 12)

The roll angle estimation device of claim 12, wherein the arithmetic circuitry estimates the rotation speed Vr of the rear wheel at a point where the rear wheel contacts a road surface, using
V
r
=
V
f
2
+
V
f
4
-
4
⁢
⁢
La
2
⁢
g
2
⁢
tan
2
⁢
ϕ
2
,
wherein
Vf is the rotation speed of the front wheel at a point where the front wheel contacts the road surface,
La is a wheelbase length of the moving body,
g is the magnitude of gravitational acceleration,
ϕ is the estimated previous value of the roll angle from the previous estimation operation, and
Vf4≥4La2g2 tan2ϕ.

### Claim 17 (depends on 16)

The roll angle estimation device of claim 16, wherein the arithmetic circuitry further estimates the rotation speed Vr of the rear wheel at the point where the rear wheel contacts the road surface using Vf/√{square root over (2)}, when Vf4<4La2g2 tan2ϕ.

### Claim 18 (depends on 1)

The roll angle estimation device of claim 1, wherein the at least one offset error includes a roll angular velocity sensor offset br, a yaw angular velocity sensor offset by and a vertical acceleration sensor offset bz, and the extending of the Kalman filter takes into account the roll angular velocity sensor offset br, the yaw angular velocity sensor offset by and the vertical acceleration sensor offset bz.