A scooter turning assist control method

Abstract

The present invention discloses a scooter turning assistance control method, comprising the following steps: S1, measuring the horizontal inclination angle of the skateboard and the angle of the skateboard bridge through a sensor; S2, calculating the estimated speed of the skateboard with reference to the torque on the wheel by combining an acceleration sensor and a speed sensor; S3, calculating the steering angle and turning radius of the skateboard after inputting fixed data of the left and right wheelbases and the front and rear axle distances of the skateboard; S4, calculating the inner wheelbase and outer wheelbase through the turning radius, thereby calculating the wheel speeds of the left and right wheels; S5, a processor adjusts the speeds of the left and right wheels based on the calculated wheel speeds, thereby completing the turning assistance. The advantages of the present invention over the prior art are: a method for calculating the turning radius of a four-wheel electric skateboard and estimating the speeds of the left and right wheels by detecting the horizontal inclination angle of the skateboard, and this method can be used as a steering assist for a skateboard, can effectively improve the efficiency of turning, reduce the difficulty of operating the scooter, and has a good market prospect.

Description

Technical Field

[0001] The invention relates to the field of electric four-wheeled skateboards, and in particular to a scooter turning power-assistance control method. Background Art

[0002] Electric skateboards are based on traditional four-wheeled skateboards, equipped with an electric powertrain. They are generally available in two-wheel or single-wheel drive configurations, with the most common drive modes being hub motors (HUBs) and belt drives. Their primary power source is a lithium battery pack. However, steering an electric skateboard requires considerable skill. Traditional electric scooters require the user to lean to achieve the desired angle, but this approach can be dangerous and laborious, requiring prolonged leaning on steep curves. Therefore, research is urgently needed on power-assisted turning control methods for electric scooters. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a scooter turning power assistance control method in view of the above problems.

[0004] In order to solve the above technical problems, the present invention provides a technical solution: a scooter turning power control method, comprising the following steps:

[0005] S1, measuring the horizontal inclination angle of the skateboard and the angle of the skateboard bridge through sensors;

[0006] S2, calculating the estimated speed of the skateboard by combining the acceleration sensor and the speed sensor with reference to the wheel torque;

[0007] S3, calculating the steering angle and turning radius of the skateboard after inputting fixed data of the left and right wheelbases and the front and rear bridge distances of the skateboard;

[0008] S4. Calculate the inner wheelbase and outer wheelbase based on the turning radius, and thereby calculate the wheel speeds of the left and right wheels;

[0009] S5. The processor adjusts the speed of the left and right wheels based on the calculated wheel speed to assist in turning.

[0010] As an improvement, the horizontal inclination angle of the skateboard is recorded as θ L , the equivalent angle when turning is θ BP , the current speed is recorded as S, the left and right wheelbase of the skateboard (the distance from the center of the left and right wheels) is recorded as D WB The distance between the front and rear axles of the skateboard (the distance between the center of the front and rear wheels) is recorded as D AB , the steering angle of the skateboard, denoted as θ T, establish a spatial rectangular coordinate system at the midpoint of the bridge pole axis. If the movement of the wheel center on the X, Y, and Z axes when turning compared to when driving straight is recorded as x', y', and z', the following formula can be obtained:

[0011] tan(θ T )=x' / (D WB / 2+z')

[0012] tan(θ L )=y' / (D WB / 2+z')

[0013] tan(θ BP )=x' / y'

[0014] Combining them we get:

[0015] x'=y'*tan(θ BP )

[0016] y'=x' / tan(θ BP )

[0017] tan(θ L )=x' / tan(θ BP ) / (D WB / 2+z')

[0018] so:

[0019] x'=tan(θ L )*tan(θ BP )*(D WB / 2+z')

[0020] tan(θ T )=tan(θ L )*tan(θ BP )*(D WB / 2+z') / (D WB / 2+z')

[0021] tan(θ T )=tan(θ L )*tan(θ BP )

[0022] θ T =tan-1(tan(θ L )*tan(θ BP ))

[0023] As an improvement, the turning radius R, ignoring the plate deformation and installation error, is considered that the steering angle of the front and rear axles is T Similarly, through trigonometric functions, we can find: R = D AB / 2 / sin(θ T ), D AB For the outer wheelbase.

[0024] As an improvement, the radius of the circle through which the left wheel moves is R L =RD WB , the radius of the circle that the right wheel moves through is R R =R+D WB Since the average speed S of the left and right wheels is known, the ideal speed S of the left wheel can be obtained. L =S*(R L / R), ideal speed of right wheel S R =S*(R R / R), the actual throttle gain of the left and right wheels = input throttle * (S R or S L ) / S.

[0025] The advantages of the present invention over the prior art are: a method for calculating the turning radius of a four-wheeled electric skateboard and estimating the speeds of the left and right steering wheels by detecting the horizontal inclination angle of the skateboard. This method can be used as a steering assist for the skateboard and can also be used in other electric skateboard automatic control algorithms. It can effectively improve the efficiency of turning, reduce the difficulty of operating the scooter, and has a good market prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a schematic diagram of the angle of a skateboard bridge of a scooter turning power-assistance control method.

[0027] Figure 2 The present invention is a schematic diagram of the horizontal inclination angle of a skateboard for a scooter turning power-assistance control method.

[0028] Figure 3 The present invention is a schematic diagram of a steering angle of a scooter in a scooter turning power-assistance control method.

[0029] Figure 4 It is a turning radius diagram of a scooter turning power control method.

[0030] Figure 5 This is an angle diagram of a skateboard bridge. DETAILED DESCRIPTION

[0031] The present invention will be described in further detail below with reference to the accompanying drawings.

[0032] In a specific implementation of the present invention, a scooter turning assist control method includes the following steps:

[0033] S1, measuring the horizontal inclination angle of the skateboard and the angle of the skateboard bridge through sensors;

[0034] S2, calculating the estimated speed of the skateboard by combining the acceleration sensor and the speed sensor with reference to the wheel torque;

[0035] S3, calculating the steering angle and turning radius of the skateboard after inputting fixed data of the left and right wheelbases and the front and rear bridge distances of the skateboard;

[0036] S4. Calculate the inner wheelbase and outer wheelbase based on the turning radius, and thereby calculate the wheel speeds of the left and right wheels;

[0037] S5. The processor adjusts the speed of the left and right wheels based on the calculated wheel speed to assist in turning.

[0038] As an improvement, the horizontal inclination angle of the skateboard is recorded as θ L , the equivalent angle when turning is θ BP , the current speed is recorded as S, the left and right wheelbase of the skateboard (the distance from the center of the left and right wheels) is recorded as D WB The distance between the front and rear axles of the skateboard (the distance between the center of the front and rear wheels) is recorded as D AB , the steering angle of the skateboard, denoted as θ T , establish a spatial rectangular coordinate system at the midpoint of the bridge pole axis. If the movement of the wheel center on the X, Y, and Z axes when turning compared to when driving straight is recorded as x', y', and z', the following formula can be obtained:

[0039] tan(θ T )=x' / (D WB / 2+z')

[0040] tan(θ L )=y' / (D WB / 2+z')

[0041] tan(θ BP )=x' / y'

[0042] Combining them we get:

[0043] x'=y'*tan(θ BP )

[0044] y'=x' / tan(θ BP )

[0045] tan(θ L )=x' / tan(θ BP ) / (D WB / 2+z')

[0046] so:

[0047] x'=tan(θ L )*tan(θ BP )*(D WB / 2+z')

[0048] tan(θ T )=tan(θ L )*tan(θ BP )*(D WB / 2+z') / (D WB / 2+z')

[0049] tan(θ T )=tan(θ L )*tan(θ BP )

[0050] θ T =tan-1(tan(θ L )*tan(θ BP ))

[0051] As an improvement, the turning radius R, ignoring the plate deformation and installation error, is considered that the steering angle of the front and rear axles is T Similarly, through trigonometric functions, we can find: R = D AB / 2 / sin(θ T ), D AB For the outer wheelbase.

[0052] As an improvement, the radius of the circle through which the left wheel moves is R L =RD WB , the radius of the circle that the right wheel moves through is R R =R+D WB Since the average speed S of the left and right wheels is known, the ideal speed S of the left wheel can be obtained. L =S*(R L / R), ideal speed of right wheel S R =S*(R R / R), the actual throttle gain of the left and right wheels = input throttle * (S R or S L ) / S.

[0053] The working principle of this invention: Before entering the actual algorithm, we need to establish a coordinate system. For ease of analysis, we use the left-right direction of the skateboard as the Z-axis, the front-back direction as the X-axis, and the up-down direction as the Y-axis. The midpoint of the line connecting the left and right wheel centers of the skateboard is used as the origin. We also need to know some skateboard data. This data includes the skateboard's physical structure and its real-time status.

[0054] The angle of the skateboard bridge is the angle between the perpendicular line of the skateboard bridge's main pin on the plane determined by the XY axis (that is, the rotation axis of the bridge rod when the skateboard turns) and the skateboard surface (the base of the bridge) (as shown by the red line in the figure below), which is recorded as θ BPWhile skateboard bridges come in a variety of configurations, they're all largely similar. This article only describes the most common type; similar methods can be used to calculate equivalent angles for other configurations.

[0055] At the same time, because the bridge rod is perpendicular to its rotation axis, when the skateboard turns, the angle between the line from the origin to the wheel center (when not turning, this line is parallel to the Z axis, and its projection in this plane is a point, and there is no connecting line) and the Y axis in the plane determined by the XY axis will always be equal to θ BP ,like Figure 1 shown.

[0056] Through sensor data, the required real-time data includes:

[0057] The horizontal inclination angle of the skateboard is the angle between the line from the origin to the wheel center and the plane determined by the Z axis on the YZ axis (such as Figure 2 ), denoted as θ L .

[0058] Current speed S (average speed of the driving wheels or estimated speed calculated by the anti-skid system).

[0059] Calculation process:

[0060] In the actual algorithm, we first calculate the angle between the line from the origin to the wheel center and the plane determined by the Z axis on the XZ axis, which is the steering angle of the skateboard, recorded as θ T (like Figure 3 shown).

[0061] The calculation process is as follows

[0062] If the movement of the wheel center on the X, Y, and Z axes when turning is compared with that when driving straight, it is recorded as x', y', and z', and the following formula can be obtained:

[0063] tan(θ T )=x' / (D WB / 2+z')

[0064] tan(θ L )=y' / (D WB / 2+z')

[0065] tan(θ BP )=x' / y'

[0066] Combining them we get:

[0067] x'=y'*tan(θ BP )

[0068] y'=x' / tan(θ BP )

[0069] tan(θ L)=x' / tan(θ BP ) / (D WB / 2+z')

[0070] so:

[0071] x'=tan(θ L )*tan(θ BP )*(D WB / 2+z')

[0072] tan(θ T )=tan(θ L )*tan(θ BP )*(D WB / 2+z') / (D WB / 2+z')

[0073] tan(θ T )=tan(θ L )*tan(θ BP )

[0074] θ T =tan-1(tan(θL)*tan(θ BP ))

[0075] Since θ L and θ BP So θ T It can be calculated.

[0076] In the calculation of θ T Then we need to calculate the turning radius R of the skateboard. Here we consider the ideal situation, ignore the deformation of the board and the installation error, and assume that the steering angle of the front and rear axles is θ T The turning situation of the skateboard at this time is as follows Figure 4 As shown:

[0077] Through trigonometric functions, we can find that: R = D AX / 2 / sin(θ T )

[0078] Finally, calculate the ideal speed of the left and right wheels. Again, taking the situation shown in the figure above as an example, the radius of the circle that the left wheel moves through relative to the center of the turning circle is R L =RD WB , the radius of the circle that the right wheel moves through is R R =R+D WB Since the average speed S of the left and right wheels is known, the ideal speed S of the left wheel can be obtained. L =S*(R L / R), ideal speed of right wheel S R =S*(R R / R), the actual throttle gain of the left and right wheels = input throttle * (S R or S L ) / S.

[0079] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A scooter turning assist control method, characterized in that: The following steps are involved: S1, measure the horizontal inclination angle of the skateboard through the sensor; S2, calculating the estimated speed of the skateboard by combining the acceleration sensor and the speed sensor with reference to the wheel torque; S3, calculating the steering angle and turning radius of the skateboard after inputting fixed data of the left and right wheelbases of the skateboard, the angle of the skateboard bridge, and the front and rear bridge distances of the skateboard; S4. Calculate the inner wheelbase and outer wheelbase based on the turning radius, and thereby calculate the wheel speeds of the left and right wheels; S5. The processor adjusts the speed of the left and right wheels based on the calculated wheel speed to assist in turning. The horizontal inclination angle of the skateboard is denoted as θ L , the equivalent angle of the skateboard bridge during steering is θ BP , the current speed is recorded as S, the left and right wheelbase of the skateboard (the distance from the center of the left and right wheels) is recorded as D WB The distance between the front and rear axles of the skateboard (the distance between the center of the front and rear wheels) is recorded as D AB , the steering angle of the skateboard, denoted as θ T , establish a spatial rectangular coordinate system at the midpoint of the bridge pole axis. If the movement of the wheel center on the X, Y, and Z axes when turning compared to when driving straight is recorded as x', y', and z', the following formula can be obtained: and(θ T )=x' / (D WB / 2+z′) and(θ L )=y' / (D WB / 2+z′) tan(θ BP )=x' / y' Combining them we get: x'=y'*tan(θ BP ) y'=x' / tan(θ BP ) and(θ L )=x' / tan(θ BP ) / (D WB / 2+z′) so: x′=tan(θ L )*and(θ BP )*(D WB / 2+z′) and(θ T )=tan(θ L )*and(θ BP )*(D WB / 2+z′) / (D WB / 2+z′) tan(θ T )=time(θ L )*time(θ BP ) θ T =time-1(time(θ L )*time(θ BP )); Turning radius R, ignoring the board deformation and installation error, assuming that the steering angle of the front and rear axles is θ T Similarly, through trigonometric functions, we can find: R = D AB / 2 / sin(θ T ), D AB For the outer wheelbase.

2. A scooter turning assist control method according to claim 1, characterized in that: The radius of the circle that the revolver moves through is R L =RD WB , the radius of the circle that the right wheel moves through is R R =R+D WB， Since the average speed S of the left and right wheels is known, the ideal speed S of the left wheel can be obtained. L =S*(R L / R), ideal speed of right wheel S R =S*(R R / R), the actual throttle gain of the left and right wheels = input throttle * (S R or S L ) / S.

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