Method for detecting low-speed running, static and unloading states of muck truck

Abstract

The invention discloses a method for detecting low-speed running, static and unloading states of a slag car. The method comprises the following steps: S1, acquiring a vibration frequency mean value f0 and an amplitude mean value A0 of the car in a static state; s2, obtaining a function of a relative distance between the bottom of a vehicle head and the ground along with time change based on an ultrasonic sensor after the vehicle is started; s3, feature extraction is carried out on the function in the S2, and the relative distance d0 between the vehicle head and the ground when the vehicle is started, the relative distance d (t) between the vehicle head and the ground at the t moment, the vibration frequency f (t) of the vehicle and the amplitude A (t) of the vehicle are extracted; and S4, based on d0, f0, A0, d (t), f (t) and A (t), judging whether the vehicle is in a low-speed running state, a static state or an unloading state. According to the method, the change of the distance between the front end of the vehicle and the ground is measured through an ultrasonic sensor, and the current state of the vehicle in the low-speed running state, the static unloading state and the static non-unloading state is judged by combining the vibration characteristics of the vehicle; the vehicle-mounted auxiliary brake system is prevented from being triggered by mistake or the brake is not intervened in time.

Description

Technical Field

[0001] The invention relates to the field of traffic safety, and in particular to a method for detecting the low-speed driving, stationary and unloading states of a muck truck based on an ultrasonic sensor. Background Art

[0002] In the actual operation of large trucks such as muck trucks, especially when driving at extremely low speeds (such as less than 4km / h), traditional speed detection methods (such as wheel speed sensors based on ABS systems) often fail to provide accurate speed data. Since the ABS sensor fails or is not applicable to the extremely low speed range, it is difficult to effectively distinguish between the low-speed driving and stationary states of the vehicle. The auxiliary braking system relies on accurate speed data to determine whether to enable the brakes. The brakes should not be triggered when the vehicle is stationary, but should be intervened in time when driving at low speeds. If the three states of low-speed driving, stationary unloading, and stationary non-unloading cannot be accurately distinguished, the auxiliary braking system may misjudge, thereby affecting vehicle safety and work efficiency.

[0003] In view of this, the present invention is proposed. Summary of the invention

[0004] In response to the problems existing in the prior art, the present invention proposes a method for detecting the low-speed driving, stationary and unloading states of a dump truck. The method uses an ultrasonic sensor to measure the change in the distance between the front end of the vehicle and the ground, and combines the vehicle's vibration characteristics to determine whether the vehicle is currently in a low-speed driving, stationary unloading or stationary not unloading state, thereby providing accurate vehicle speed information and state judgment for the on-board auxiliary braking system to avoid false triggering of braking or failure to intervene in braking in time.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for detecting the low-speed driving, stationary and unloading states of a muck truck, comprising the following steps:

[0007] S1. Obtain the average vibration frequency f0 and the average amplitude A0 of the vehicle in a stationary state;

[0008] S2, a function of the relative distance between the bottom of the vehicle head and the ground changing with time after the vehicle starts, obtained based on the ultrasonic sensor;

[0009] S3, extracting features of the function in S2, extracting the relative distance d0 between the front of the vehicle and the ground when the vehicle starts, the relative distance d(t) between the front of the vehicle and the ground at time t, the vibration frequency f(t) of the vehicle, and the amplitude A(t) of the vehicle;

[0010] S4. Based on d0, f0, A0, d(t), f(t) and A(t), determine whether the vehicle is traveling at a low speed, stationary or unloading.

[0011] Furthermore, in S2, the echo signal and the echo time collected by the ultrasonic sensor are converted into a function of the distance between the bottom of the vehicle head and the ground varying with time.

[0012] Furthermore, in S4, the step of determining the vehicle state is:

[0013] S41, judging whether the vehicle is in a stationary state by d0 and d(t); if the judgment result is that the vehicle is not in a stationary state, proceeding to S42;

[0014] S42. Determine whether the vehicle is in a low-speed driving state or a cargo unloading state through f0, A0, f(t) and A(t).

[0015] Furthermore, in S41, the specific method for determining whether the vehicle is in a stationary state is as follows: at time t, when d(t) and d0 satisfy the following formula, it is determined that the vehicle is in a stationary state;

[0016]

[0017] Otherwise, go to S42.

[0018] Further, in S42, the specific method for determining whether the vehicle is in a low-speed driving state or a cargo unloading state is as follows: at time t, when f0, A0, f(t) and A(t) satisfy the following formula, it is determined that the vehicle is in a low-speed driving state;

[0019]

[0020] Otherwise, the vehicle is determined to be in the unloading state.

[0021] Furthermore, the ultrasonic sensor is installed at the bottom of the front of the vehicle, vertically facing the ground, and 10 cm away from the inner side of the tire.

[0022] Furthermore, in S3, when the ultrasonic sensor collects the echo signal, the collected echo signal needs to be preprocessed.

[0023] Furthermore, the specific method of preprocessing the collected echo signal is: performing noise filtering and data smoothing on the echo signal.

[0024] Furthermore, in S1, f0 and A0 are acquired based on the ultrasonic sensor.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention measures the change in the distance between the front end of the vehicle and the ground, analyzes the vibration characteristics of the vehicle body, and accurately distinguishes between the three states of extremely low speed driving, stationary unloading, and stationary without unloading, thereby optimizing the response of the auxiliary braking system and improving the safety and stability of the vehicle; when driving at a low speed, the vibration frequency and amplitude of the vehicle are significantly different from those in the stationary state; while in the stationary unloading state, the operation of the hydraulic push rod will cause the vehicle body to produce a vibration mode different from that in the stationary state; through real-time monitoring and analysis of these vibration characteristics, the driving state of the vehicle can be accurately judged, providing reliable data support for the auxiliary braking system, avoiding misbraking or lack of brake intervention, and improving the safety and operating efficiency of the muck truck. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0028] Figure 1 Flow chart of the detection method of the present invention. DETAILED DESCRIPTION

[0029] The embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention.

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0031] In the following description, specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in a variety of other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0032] refer to Figure 1 This example proposes a method for detecting the low-speed driving, stationary and unloading states of a muck truck, including the following steps:

[0033] S1. Collect historical data to obtain the average vibration frequency f0 and the average amplitude A0 of the vehicle in a stationary state; specifically, the ultrasonic sensor can be installed at the bottom of the front of the vehicle, facing the ground vertically, 10 cm away from the inner side of the tire, start the vehicle, and collect echo signals through the ultrasonic sensor. During the collection process, the echo signals are subjected to noise filtering and data smoothing. The collected echo signals and callback time are converted into a function of the relative distance between the front of the vehicle and the ground changing with time when the vehicle is stationary. The function is feature extracted to obtain the average vibration frequency f0 and the average amplitude A0 of the vehicle in a stationary state; the stationary time of the vehicle can be flexibly adjusted according to needs; the setting of the installation position of the ultrasonic sensor in this embodiment can prevent the uneven ground from causing large error in the results, and the installation position can be selected according to needs in actual use;

[0034] S2. When the vehicle is in use, the ultrasonic sensor in S1 is used to obtain a function of the relative distance between the bottom of the vehicle head and the ground changing with time after the vehicle is started. The specific method is: the echo signal and echo time collected by the ultrasonic sensor are converted into a function of the distance between the bottom of the vehicle head and the ground changing with time, and the echo signal is subjected to noise filtering and data smoothing during the collection process;

[0035] S3, extracting features of the function in S2, extracting the relative distance d0 between the front of the vehicle and the ground when the vehicle starts, the relative distance d(t) between the front of the vehicle and the ground at time t, the vibration frequency f(t) of the vehicle, and the amplitude A(t) of the vehicle;

[0036] S4. Based on d0, f0, A0, d(t), f(t) and A(t), determine whether the vehicle is in a low-speed driving, stationary or unloading state; since the muck truck has different vibration characteristics in the three states of low-speed driving, stationary and unloading, the changes in the vehicle vibration frequency and amplitude are relatively stable when the vehicle is stationary; the vibration frequency and amplitude fluctuate greatly when the vehicle is driving at a low speed; when the vehicle is in the unloading state, due to the action of the vehicle hydraulic booster push rod, the center of gravity of the vehicle body moves backward, resulting in a larger relative distance between the bottom of the vehicle head and the ground, and the vibration frequency and amplitude of the vehicle will also change, so the analysis of the vibration characteristics of the muck truck can accurately obtain the current state of the vehicle; in this example, the specific method for determining whether the vehicle is in a low-speed driving, stationary or unloading state is:

[0037] First, use the following formula to determine whether the vehicle is stationary at time t; when d(t) and d0 meet the following requirements, the vehicle is determined to be stationary;

[0038]

[0039] Otherwise, the vehicle is in a low-speed driving or unloading state;

[0040] Then use the following formula to determine whether the vehicle is in a low-speed driving state or unloading state at time t; when f0, A0, f(t) and A(t) meet the requirements of the following formula, it is determined that the vehicle is in a low-speed driving state;

[0041]

[0042] Otherwise, the vehicle is determined to be in the unloading state.

[0043] Although the present invention has been described in detail in this specification by means of general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto on the basis of the present invention. Therefore, these modifications or improvements made without departing from the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A method for detecting a muck truck in low-speed driving, stationary and unloading states, characterized in that: The following steps are involved: S1. Obtain the average vibration frequency f0 and the average amplitude A0 of the vehicle in a stationary state; S2, a function of the relative distance between the bottom of the vehicle head and the ground changing with time after the vehicle starts, obtained based on the ultrasonic sensor; S3, extracting features of the function in S2, extracting the relative distance d0 between the front of the vehicle and the ground when the vehicle starts, the relative distance d(t) between the front of the vehicle and the ground at time t, the vibration frequency f(t) of the vehicle, and the amplitude A(t) of the vehicle; S4. Based on d0, f0, A0, d(t), f(t) and A(t), determine whether the vehicle is traveling at a low speed, stationary or unloading.

2. A method for detecting the low-speed driving, stationary and unloading states of a muck truck according to claim 1, characterized in that: In S2, the echo signal and echo time collected by the ultrasonic sensor are converted into a function of the distance between the bottom of the vehicle head and the ground changing with time.

3. The method for detecting the low-speed driving, stationary and unloading states of a muck truck according to claim 1, characterized in that: In S4, the steps of determining the vehicle status are: S41, judging whether the vehicle is in a stationary state by d0 and d(t); if the judgment result is that the vehicle is not in a stationary state, proceeding to S42; S42. Determine whether the vehicle is in a low-speed driving state or a cargo unloading state through f0, A0, f(t) and A(t).

4. A method for detecting the low-speed driving, stationary and unloading states of a muck truck according to claim 3, characterized in that: In S41, the specific method for determining whether the vehicle is in a stationary state is as follows: at time t, when d(t) and d0 satisfy the following formula, it is determined that the vehicle is in a stationary state; Otherwise, go to S42.

5. The method for detecting the low-speed driving, stationary and unloading states of a muck truck according to claim 3, characterized in that: In S42, the specific method for determining whether the vehicle is in a low-speed driving state or a cargo unloading state is as follows: at time t, when f0, A0, f(t) and A(t) satisfy the following formula, the vehicle is determined to be in a low-speed driving state; Otherwise, the vehicle is determined to be in the unloading state.

6. The method for detecting the low-speed driving, stationary and unloading states of a muck truck according to claim 1, characterized in that: The ultrasonic sensor is installed at the bottom of the front of the vehicle, vertically facing the ground, and 10 cm away from the inner side of the tire.

7. The method for detecting the low-speed driving, stationary and unloading states of a muck truck according to claim 2, characterized in that: In S3, when the ultrasonic sensor collects the echo signal, the collected echo signal needs to be preprocessed.

8. The method for detecting the low-speed driving, stationary and unloading states of a muck truck according to claim 7, characterized in that: The specific method for preprocessing the collected echo signal is: performing noise filtering and data smoothing on the echo signal.

9. The method for detecting the low-speed driving, stationary and unloading states of a muck truck according to claim 1, characterized in that: In S1, f0 and A0 are acquired based on the ultrasonic sensor.

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