An anti-overturning sonar warning control method for self-balancing intelligent electric vehicles

Abstract

The present invention relates to an anti-overturning sonar warning control method for a self-balancing intelligent electric vehicle, which includes: after the self-balancing intelligent electric vehicle starts, the on-vehicle double flywheel rotates at a high speed; the main controller calculates the road surface inclination angle of the traveling path; calculates the balance torque required for smooth driving on this road surface, and determines whether the required balance torque is less than or equal to a first threshold. If it is less than or equal to the first threshold, the self-balancing electric vehicle continues to move forward in the direction of the traveling path; the main controller calculates the centrifugal force compensation, and determines whether the balance torque required for smooth driving on the traveling path is less than or equal to a second threshold. If it is less than or equal to the second threshold, the self-balancing electric vehicle continues to move forward in the direction of the traveling path, otherwise, an alarm is given. The present invention can make the self-balancing electric vehicle run more stably, can conduct a preliminary exploration of unknown road conditions, and prevent irreversible impacts on autonomous driving caused by sudden complex terrain changes.

Description

Technical Field

[0001] The present invention relates to the technical fields of balance control and artificial intelligence autonomous driving, and particularly to an anti-overturning sonar warning control method for a self-balancing intelligent electric vehicle. Background Art

[0002] At present, life is developing towards the direction of intelligence and convenience. Self-balancing intelligent electric vehicles also conform to this trend, following the trend of the times and having good development prospects. The most unique feature of self-balancing intelligent electric vehicles compared to other means of transportation is energy conservation and environmental protection. Nowadays, global warming will bring a devastating disaster to the earth, and one of the main culprits of rising temperatures is the large amount of industrial waste gas emissions. The emissions of automobile exhaust gas in means of transportation are also one of the important reasons. Another crisis in the world today is the energy crisis. It is an inevitable trend for energy-saving and environment-friendly means of transportation to replace the traditional ones, providing broad development space for the development of self-balancing intelligent electric vehicles. However, current self-balancing intelligent electric vehicle products only focus on their appearance and simple balance control algorithms, and the stability of the products is not high, and their degree of intelligence needs to be improved. Summary of the Invention

[0003] The purpose of the present invention is to provide an anti-overturning sonar warning control method for a self-balancing intelligent electric vehicle, which can make the self-balancing electric vehicle run more stably, prevent irreversible effects on autonomous driving caused by sudden complex terrain changes, and effectively protect the safety of vehicle occupants.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions: An anti-overturning sonar warning control method for a self-balancing intelligent electric vehicle, the method includes the following steps in sequence:

[0005] (1) After the self-balancing intelligent electric vehicle starts, the vehicle-mounted double flywheel rotates at a high speed, and the balance torque generated by the vehicle-mounted double flywheel is set as the first threshold;

[0006] (2) The self-balancing intelligent electric vehicle scans the road surface ahead through the sound wave signal emitted by the high-speed rotation of the vehicle-mounted double flywheel. The vehicle-mounted sonar detector receives the sound wave signal reflected by the road surface ahead and transmits it into the main controller. The main controller calculates the road surface inclination angle θ of the traveling path. lean ;

[0007] (3) The main controller calculates the balance torque required for stable driving on this road surface according to the road surface inclination angle θ of the traveling path. lean And determines whether the required balance torque is less than or equal to the first threshold. If the required balance torque is less than or equal to the first threshold, the self-balancing electric vehicle continues to move forward in the direction of the traveling path; otherwise, enter the next step;

[0008] (4) The main controller calculates the centrifugal force compensation, adds the centrifugal force compensation to the first threshold to obtain the second threshold, and determines whether the balance torque required for smooth driving on the traveling path is less than or equal to the second threshold. If the required balance torque is less than or equal to the second threshold, the self-balancing electric vehicle continues to move forward in the direction of the traveling path. Otherwise, the main controller displays the judgment result and a red alarm on the display screen, adjusts the direction at the same time, plans a new path, and returns to step (2).

[0009] Specifically, step (2) means that the on-vehicle sonar detector estimates the time difference of the acoustic wave signal reaching three array elements by using the triple sonar array ranging method according to the returned acoustic wave signal, so as to inversely deduce the position of the target sound source. The three array elements are the first array element, the second array element, and the third array element. All three array elements are installed in the on-vehicle sonar detector, the array element spacing is d, and the distance from the target sound source to the second array element is the target distance R to be measured;

[0010] The calculation formula for the target distance R is:

[0011]

[0012] where τ 12 is the time difference between the acoustic wave signal reaching the first array element and the second array element, τ 23 is the time difference between the acoustic wave signal reaching the second array element and the third array element, and c is the propagation speed of the acoustic wave signal;

[0013] Converting the target distance R into the handlebar rotation angle gives:

[0014]

[0015] where w is the body length of the self-balancing electric vehicle, γ is the handlebar rotation angle, and g is the acceleration due to gravity;

[0016] After obtaining the handlebar rotation angle, the road surface inclination angle θ of the traveling path is obtained from the following formula lean :

[0017]

[0018] where v is the traveling speed of the self-balancing electric vehicle.

[0019] In step (3), the calculation formula for the first threshold is:

[0020] e θ = θ e + θ d - θ

[0021]

[0022]

[0023] Where: T sum is the total rolling moment generated by the front and rear double flywheels, i.e., the first threshold; k P and k D are the output control gains for controlling the rotation of the double flywheels, θ is the maximum tilt angle at which the self-balancing electric vehicle can maintain balance, θ d is the desired tilt angle; θ e is the tilt angle compensation;

[0024] When the main controller calculates the balance moment T actual required for smooth driving on the travel path, θ in the above formula is the front road surface tilt angle θ lean .

[0025] The specific step (4) refers to:

[0026] The centrifugal force compensation includes two aspects: the centrifugal moment related to the front wheel steering angle and the centrifugal moment related to the front wheel steering angular velocity Where

[0027]

[0028] T dψ =-K f3 ·J A,a-xz ·(tanψ fs )′·v rw

[0029]

[0030]

[0031] S A,a-z =-m a ·h rw-a

[0032] Where, r fw is the front wheel radius, r rw is the rear wheel radius, θ fs is the front fork angle, is the moment of inertia of the front wheel about the rotation axis, is the moment of inertia of the rear wheel about the rotation axis, ψ fs is the front wheel steering angle, v rw is the vehicle speed, S A,a-z is the z-component of the first moment of the loaded vehicle relative to the rear wheel contact point, J A,a-xz is the component of the moment of inertia of the loaded vehicle relative to the rear wheel contact point, K f0 is the z-component of the first moment of the loaded vehicle relative to the rear wheel contact point;

[0033] The adjusted total output torque is as follows:

[0034] T sum+li = T sum + T ψ + T dψ

[0035] T sum+li That is, the second threshold value.

[0036] As can be seen from the above technical solution, the beneficial effects of the present invention are as follows: First, the present invention can make the self-balancing electric vehicle run more stably, can pre-explore unknown road conditions, and prevent irreversible impacts on autonomous driving caused by sudden complex terrain changes; Second, the present invention can automatically determine whether the terrain ahead meets the traveling requirements of the electric vehicle. If not, it will automatically find the next path, making it more intelligent, and at the same time can effectively protect the safety of the vehicle occupants. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a flowchart of the method of the present invention;

[0038] Figure 2 is a schematic diagram of the overall structure of the self-balancing electric vehicle. DETAILED DESCRIPTION OF THE INVENTION

[0039] As Figure 1 , 2 shown, an anti-overturning sonar warning control method for a self-balancing intelligent electric vehicle, the method includes the following steps in sequence:

[0040] (1) After the self-balancing intelligent electric vehicle starts, the on-vehicle double flywheel 3 rotates at a high speed, so that the vehicle body of the electric vehicle is kept in a balanced position, and the functions of movement and turning and obstacle avoidance are realized through rear-wheel drive and handlebar rotation. Let the balancing torque generated by the on-vehicle double flywheel 3 be the first threshold value;

[0041] (2) The self-balancing intelligent electric vehicle scans the road surface ahead through the sound wave signal emitted by the high-speed rotation of the on-vehicle double flywheel 3. The on-vehicle sonar detector 1 receives the sound wave signal reflected by the road surface ahead and transmits it into the main controller 2. The main controller 2 calculates the road surface inclination angle θ of the traveling path lean ;

[0042] (3) The main controller 2 calculates the balancing torque required for stable driving on the road surface according to the road surface inclination angle θ of the traveling path lean , and judges whether the required balancing torque is less than or equal to the first threshold value. If the required balancing torque is less than or equal to the first threshold value, the self-balancing electric vehicle continues to move forward in the direction of the traveling path; otherwise, it enters the next step;

[0043] (4) The main controller 2 calculates the centrifugal force compensation, adds the centrifugal force compensation to the first threshold to obtain the second threshold, and determines whether the balance torque required for smooth driving on the travel path is less than or equal to the second threshold. If the required balance torque is less than or equal to the second threshold, the self-balancing electric vehicle continues to move forward in the direction of the travel path. Otherwise, the main controller 2 displays the judgment result and a red alert on the display screen, adjusts the direction at the same time, plans a new path, and returns to step (2).

[0044] Specifically, step (2) means that the vehicle-mounted sonar detector 1 uses the three-element sonar array ranging method according to the returned sound wave signal to estimate the time difference of the sound wave signal reaching three array elements to inversely deduce the position of the target sound source. The three array elements are the first array element, the second array element, and the third array element. All three array elements are installed in the vehicle-mounted sonar detector 1, the array element spacing is d, and the distance from the target sound source to the second array element is the target distance R to be measured;

[0045] The calculation formula for the target distance R is:

[0046]

[0047] where τ 12 is the time difference of the sound wave signal reaching the first array element and the second array element, τ 23 is the time difference of the sound wave signal reaching the second array element and the third array element, and c is the propagation speed of the sound wave signal;

[0048] The target distance R is converted into the handlebar rotation angle to obtain:

[0049]

[0050] where w is the body length of the self-balancing electric vehicle, γ is the handlebar rotation angle, and g is the acceleration due to gravity;

[0051] After obtaining the handlebar rotation angle, the road surface inclination angle θ of the travel path is obtained from the following formula lean :

[0052]

[0053] where v is the driving speed of the self-balancing electric vehicle.

[0054] In step (3), the calculation formula for the first threshold is:

[0055] e θ = θ e + θ d - θ

[0056]

[0057]

[0058] Wherein: T sum is the total rolling moment generated by the front and rear double flywheels, i.e., the first threshold; k P and k D are the output control gains for controlling the rotation of the double flywheels, θ is the maximum tilt angle at which the self-balancing electric vehicle can maintain balance, θ d is the desired tilt angle; θ e is the tilt angle compensation amount;

[0059] When the main controller 2 calculates the balance moment T required for smooth driving on the travel path actual , θ in the above formula is the front road surface tilt angle θ lean .

[0060] The specific step (4) refers to:

[0061] The centrifugal force compensation includes two aspects: the centrifugal moment related to the front wheel steering angle and the centrifugal moment related to the front wheel steering angular velocity Wherein

[0062]

[0063] T dψ =-K f3 ·J A,a-xz ·(tanψ fs )′·v rw

[0064]

[0065]

[0066] S A,a-z =-m a ·h rw-a

[0067] Wherein, r fw is the front wheel radius, r rw is the rear wheel radius, θ fs is the front fork angle, is the moment of inertia of the front wheel about the rotation axis, is the moment of inertia of the rear wheel about the rotation axis, ψ fs is the front wheel steering angle, v rw is the vehicle speed, S A,a-z is the z-component of the first moment of the loaded vehicle relative to the rear wheel contact point, J A,a-xz is the component of the moment of inertia of the loaded vehicle relative to the rear wheel contact point, K f0 is the z-component of the first moment of the loaded vehicle relative to the rear wheel contact point;

[0068] The adjusted total output torque is as follows:

[0069] T sum+li = T sum + T ψ + T dψ

[0070] T sum+li That is, the second threshold value.

[0071] In summary, the present invention can make the self-balancing electric vehicle run more stably, can conduct a preliminary exploration of unknown road conditions, and prevent irreversible impacts on autonomous driving caused by sudden complex terrain changes; the present invention can automatically judge whether the terrain ahead meets the traveling requirements of the electric vehicle. If not, it can automatically find the next path, making it more intelligent, and at the same time can effectively protect the safety of vehicle occupants.

Claims

1. An anti-overturning sonar warning control method for a self-balancing intelligent electric vehicle, characterized in that: The method includes the following steps in sequence: (1) After the self-balancing intelligent electric vehicle starts, the on-vehicle double flywheel rotates at high speed, and the balancing torque generated by the on-vehicle double flywheel is set as the first threshold; (2) The self-balancing intelligent electric vehicle scans the road surface ahead through the sound wave signals emitted by the high-speed rotation of the on-vehicle double flywheel. The on-vehicle sonar detector receives the sound wave signals reflected by the road surface ahead and transmits them into the main controller. The main controller calculates to obtain the road surface inclination angle θ of the traveling path. lean ; (3) The main controller calculates the balance torque required for smooth driving on the road surface based on the road surface inclination angle θ of the traveling path lean calculates the balance torque required for smooth driving on this road surface, and determines whether the required balance torque is less than or equal to the first threshold. If the required balance torque is less than or equal to the first threshold, the self-balancing electric vehicle continues to move forward in the direction of the traveling path; otherwise, it proceeds to the next step; (4) The main controller calculates the centrifugal force compensation, adds the centrifugal force compensation to the first threshold to obtain the second threshold, and judges whether the balancing torque required for smooth driving on the traveling path is less than or equal to the second threshold. If the required balancing torque is less than or equal to the second threshold, the self-balancing electric vehicle continues to move forward in the direction of the traveling path. Otherwise, the main controller displays the judgment result and a red alarm on the display screen, and at the same time adjusts the direction, plans a new path, and returns to step (2).

2. The anti-overturning sonar warning control method for a self-balancing intelligent electric vehicle according to claim 1, characterized in that: The specific content of step (2) is as follows: The on-vehicle sonar detector uses the three-element sonar array ranging method according to the returned acoustic wave signal to estimate the time difference of the acoustic wave signal reaching the three array elements to inversely deduce the position of the target sound source. The three array elements are the first array element, the second array element, and the third array element. All three array elements are installed in the on-vehicle sonar detector, and the distance between the array elements is d. The distance from the target sound source to the second array element is the target distance R to be measured; The calculation formula for the target distance R is: where τ 12 is the time difference for the acoustic wave signal to reach the first and second array elements, and τ 23 is the time difference for the acoustic wave signal to reach the second and third array elements, and c is the propagation speed of the acoustic wave signal; The conversion of the target distance R to the handlebar angle is: where w is the length of the self-balancing electric vehicle body, γ is the handlebar angle, and g is the acceleration due to gravity; After obtaining the steering angle of the handlebar, the road surface inclination angle θ of the traveling path is obtained by the following formula lean :[[]]END]] where v is the traveling speed of the self-balancing electric vehicle.

3. The anti-overturning sonar warning control method for a self-balancing intelligent electric vehicle according to claim 1, characterized in that: In step (3), the calculation formula for the first threshold is: e θ = θ e + θ d - θ Where: T sum is the total rolling moment generated by the front and rear double flywheels, that is, the first threshold; k P and k D are the output control gains for controlling the rotation of the double flywheels, θ is the maximum tilt angle at which the self-balancing electric vehicle can maintain balance, θ d is the desired tilt angle; θ e is the tilt angle compensation amount; The main controller calculates the balance torque T required for smooth driving on the traveling path actual When calculating, θ in the above formula is the front road surface inclination angle θ lean .

4. The anti-overturning sonar warning control method for a self-balancing intelligent electric vehicle according to claim 1, characterized in that: The specific content of step (4) is: The centrifugal force compensation includes two aspects: the centrifugal moment related to the front wheel steering angle and the centrifugal moment related to the front wheel steering angular velocity wherein T dψ = -K f3 ·J A,a-xz ·(tanψ fs )′·v rw S A,a-z = -m a ·h rw-a Among them, r fw is the front wheel radius, r rw is the rear wheel radius, θ fs is the front fork angle, is the moment of inertia of the front wheel about the axis of rotation, is the moment of inertia of the rear wheel about the axis of rotation, ψ fs is the front wheel steering angle, v rw is the vehicle speed, S A,a-z is the z-component of the first moment of the loaded vehicle about the rear wheel contact point, J A,a-xz is the component of the moment of inertia of the loaded vehicle about the rear wheel contact point, K f0 is the z-component of the first moment of the loaded vehicle about the rear wheel contact point; The adjusted total output torque is: T sum+li = T sum + T ψ + T dψ T sum+li That is, the second threshold value.

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