CN115071421A - Vehicle speed display method and system of vehicle digital instrument - Google Patents

Abstract

The invention discloses a vehicle digital instrument speed display method and system. The method comprises the following steps: filtering a pulse signal collected by a Hall sensor on a duty cycle; The signal is converted to obtain the real-time vehicle speed; the mean value smoothing process is performed on the real-time vehicle speed to obtain the smoothed vehicle speed; according to whether the difference between the adjacent first smoothed vehicle speed and the second smoothed vehicle speed is greater than the vehicle speed update threshold, the updated vehicle speed is determined; The updated vehicle speed is refreshed every preset time, and the updated vehicle speed is displayed. In the present invention, by smoothing the mean value of the vehicle speed, the updated vehicle speed is determined according to whether the difference between the adjacent first smoothed vehicle speed and the second smoothed vehicle speed is greater than the vehicle speed update threshold, which reduces the influence of vehicle speed data jitter, and the calculation method is simple , the calculation speed is fast, the real-time performance is good, and the user experience is good.

Description

A vehicle speed display method and system of a vehicle digital instrument

technical field

The invention relates to the technical field of vehicle digital instruments, in particular to a vehicle speed display method and system of a vehicle digital instrument.

Background technique

Most commercial vehicles currently use pointer-type instruments, which display the current vehicle speed in real time through physical pointers on the instrument panel. In this way, on the one hand, it is not intuitive, and on the other hand, it requires a stepping motor to drive the pointer to rotate, and the cost is relatively high.

For this reason, digital instruments are increasingly used in commercial vehicles. In the existing digital instrument, the non-contact sensor of the gearbox odometer is usually used for speed measurement, that is, the driving speed signal is sensed and detected by the Hall element and photoelectric element on the sensor, and then the pulse signal is transmitted to the digital instrument, and passed The K value pulse coefficient is converted to obtain the actual vehicle speed for display. This scheme uses Hall sensors and corresponding circuits, and has the following defects:

Hall sensors are easily interfered by other sensors in the vehicle, resulting in sudden changes and jitters in vehicle speed data, while the response speed of digital instruments is very fast. Use experience.

In view of this, it is urgent to improve the vehicle speed display method of the existing vehicle digital instrument, so that the digital display pointer of the digital instrument runs smoothly and smoothly, the digital display is clear and stable, and has a better user experience.

SUMMARY OF THE INVENTION

In view of the above defects, the technical problem to be solved by the present invention is to provide a vehicle speed display method of a vehicle digital instrument, so as to solve the problem that the existing construction method has a great influence on the surrounding waters.

To this end, the present invention provides a vehicle speed display method of a vehicle digital instrument, comprising the following steps:

Perform duty cycle filtering on the pulse signal collected by the Hall sensor in the collection period;

Use the set K value pulse coefficient to convert the filtered pulse signal, and calculate and obtain the real-time vehicle speed of the current acquisition period;

performing mean value smoothing processing on the real-time vehicle speed to obtain a smooth vehicle speed;

Determine the updated vehicle speed according to whether the difference between the adjacent first smoothed vehicle speed and the second smoothed vehicle speed is greater than the vehicle speed update threshold; if the difference is greater than the vehicle speed update threshold, add the second smoothed vehicle speed to the difference value Half of it is used as the updated vehicle speed, otherwise, the second smoothed vehicle speed is used as the updated vehicle speed;

The updated vehicle speed is refreshed every preset time, and the updated vehicle speed is displayed.

In the above technical method, preferably, the duty cycle filtering process is to discard pulse signals with a duty cycle greater than (50+P)% and less than (50-P)%, where P is a preset filtering parameter, is a natural number greater than 1.

In the above technical method, preferably, the method for smoothing the mean value is as follows:

Take the current real-time vehicle speed Vn and the first s real-time vehicle speeds Vn-s, Vn-s+1, Vn-s+2...;

The smooth vehicle speed Vi is obtained by using the formula Vi=(Vn-s+Vn-s+1+Vn-s+2...Vn)/s, where n is a natural number greater than 2, and s is a natural number greater than 1.

In the above technical method, preferably, the vehicle speed update threshold is 1 km/h.

In the above technical method, preferably, the preset time is 500 milliseconds.

The present invention also provides a vehicle speed display system of a vehicle digital instrument, comprising:

The filtering unit is used to filter the duty cycle of the pulse signal collected by the Hall sensor in the collection period;

The conversion unit is used to convert the filtered pulse signal by using the set K value pulse coefficient, and calculate and obtain the real-time vehicle speed of the current collection period;

a smoothing unit, configured to perform mean value smoothing processing on the real-time vehicle speed to obtain a smoothed vehicle speed;

The vehicle speed determination unit is configured to determine the updated vehicle speed according to whether the difference between the adjacent first smooth vehicle speed and the second smooth vehicle speed is greater than the vehicle speed update threshold; if the difference is greater than the vehicle speed update threshold, the second smooth vehicle speed is increased. Half of the above difference is used as the updated vehicle speed, otherwise, the second smoothed vehicle speed is used as the updated vehicle speed;

The updating unit is configured to refresh the updated vehicle speed every preset time, and display the updated vehicle speed.

In the above system, preferably, the vehicle speed update threshold is 1 km/h.

In the above system, preferably, the preset time is 500 milliseconds.

It can be seen from the above technical solutions that the vehicle speed display method and system of the vehicle digital instrument provided by the present invention solve the problem of the sudden change and jitter of the digital display pointer in the prior art, which affects the customer's use experience. Compared with the prior art, the present invention has the following beneficial effects:

By smoothing the mean value of the vehicle speed, the accuracy of the vehicle speed is improved and the influence of sudden changes is avoided. Determine the updated vehicle speed according to whether the difference between the adjacent first smoothed vehicle speed and the second smoothed vehicle speed is greater than the vehicle speed update threshold, and if the difference is greater than the vehicle speed update threshold, add the second smoothed vehicle speed to the difference Half of it is used as the updated vehicle speed, otherwise, the second smoothed vehicle speed is used as the updated vehicle speed, which reduces the influence of vehicle speed data jitter. Moreover, the calculation method is simple, the calculation speed is fast, the real-time performance is good, and the user experience is good.

Description of drawings

In order to describe the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces and describes the accompanying drawings that are required in the description of the embodiments of the present invention or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can also be obtained from these drawings without creative efforts.

FIG. 1 is a flow chart of a vehicle speed display method of a vehicle digital instrument provided by the present invention.

Detailed ways

The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the embodiments described below are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

The realization principle of the present invention is:

Perform duty cycle filtering on the pulse signal collected by the Hall sensor; convert the filtered pulse signal with the set K value pulse coefficient to obtain a real-time vehicle speed; perform mean value smoothing on the real-time vehicle speed to obtain a smooth vehicle speed ; Determine the updated vehicle speed according to whether the difference between the adjacent first smoothed vehicle speed and the second smoothed vehicle speed is greater than the vehicle speed update threshold; refresh the updated vehicle speed every preset time, and display the updated vehicle speed.

By smoothing the average value of the vehicle speed, the updated vehicle speed is determined according to whether the difference between the adjacent first smoothed vehicle speed and the second smoothed vehicle speed is greater than the vehicle speed update threshold, which reduces the influence of vehicle speed data jitter, and the calculation method is simple and the calculation speed is simple. Fast, good real-time performance, and good user experience.

In order to explain and illustrate the technical solutions and implementation manners of the present invention more clearly, several preferred specific embodiments for realizing the technical solutions of the present invention are introduced below.

It should be noted that the orientation words such as "inside, outside", "front, rear" and "left and right" in this article are based on the product use state as the reference object. Obviously, the use of the corresponding orientation words protects this scheme. The scope is not intended to be limiting.

Digital instruments and Hall sensors used in existing commercial vehicles are susceptible to interference from other sensors in the vehicle, resulting in sudden changes and jitters in vehicle speed data, affecting customers' experience. In view of the above problems, the method of the present invention provides a vehicle speed display method and system of a vehicle digital instrument.

Please refer to FIG. 1. FIG. 1 is a flowchart of a vehicle speed display method of a vehicle digital instrument provided by the present invention.

As shown in FIG. 1, a vehicle speed display method of a vehicle digital instrument provided by the present invention includes the following steps:

Step 110: Perform duty cycle filtering on the pulse signal collected by the Hall sensor in the collection period.

Specifically, the pulse signal whose duty ratio is greater than (50+P)% and less than (50-P)% is discarded, where P is a preset filtering parameter, which is a natural number greater than 1. For example, when P=5, the pulse signal whose duty ratio is greater than 55% and less than 5% is discarded.

Hall sensor is a magnetoelectric sensor based on Hall effect, which has the characteristics of simple structure and convenient use. Its working principle is that when the rotating mechanism of the sensor rotates under the action of external driving, it will drive the permanent magnet to rotate, and the magnetic field passing through the Hall element will change periodically, causing the output voltage of the Hall element to change, and a stable pulse will be formed through subsequent circuit processing. The voltage signal is used as the vehicle speed output signal. The main electrical technical parameters of the Hall speed sensor include: output signal high voltage, low voltage, duty cycle, period, rise time, fall time, number of periodic pulses, etc.

The duty cycle refers to the proportion of the high level in the pulse signal collected by the Hall sensor in one collection period. By filtering the pulse signal collected by the Hall sensor on the duty cycle, the interference of other external sensors is reduced, and the accuracy of the actual vehicle speed is improved.

Step 120: Convert the filtered pulse signal by using the set K value pulse coefficient, and calculate and obtain the real-time vehicle speed of the current collection period.

The K value pulse coefficient is the number of pulse signals per kilometer.

Step 130: Perform mean value smoothing on the real-time vehicle speed to obtain a smoothed vehicle speed. The specific method is as follows:

Take the current real-time vehicle speed Vn and the first s real-time vehicle speeds Vn-s, Vn-s+1, Vn-s+2...;

Use the formula Vi=(Vn-s+Vn-s+1+Vn-s+2...Vn)/(s+1) to obtain the current smooth vehicle speed Vi, where n is a natural number greater than 2, indicating the nth Collection period, s is a natural number greater than 1, indicating the first s collection periods.

For example: the fifth collection period n=5, take the first 2 collection periods for smoothing, then add the current collection period for a total of 3 collection periods for smoothing to obtain the current smooth vehicle speed Vi=(V3+V4+V5 )/3.

Step 140: Determine the updated vehicle speed according to whether the difference between the adjacent first smoothed vehicle speed and the second smoothed vehicle speed is greater than the vehicle speed update threshold.

If the difference between the first smoothed vehicle speed and the second smoothed vehicle speed is greater than the vehicle speed update threshold, the second smoothed vehicle speed plus half of the above difference is used as the updated vehicle speed; otherwise, the second smoothed vehicle speed is used as the updated vehicle speed.

Specifically, first set a vehicle speed update threshold value t, determine whether the second smoothed vehicle speed Vi and the first smoothed vehicle speed Vi-1 are greater than or equal to the vehicle speed update threshold t, if (Vi-Vi-1)>t, then update the vehicle speed Vj =Vi+(Vi−Vi−1)/2; on the contrary, if (Vi−Vi−1)≦t, the updated vehicle speed Vj=the second smoothed vehicle speed Vi. Among them, the vehicle speed update threshold value t is a natural number, which indicates how much the vehicle speed changes before updating, and the update is smooth at the combined vehicle speed to avoid sudden changes and jitters. For example, if t is 1 km/h, the update can only be done when the speed change is greater than 1 km per hour. If the speed change does not exceed 1 km per hour, the current speed will remain unchanged.

Step 150, refresh the updated vehicle speed every preset time, and display the updated vehicle speed.

The preset time is the vehicle speed update threshold, which is used to avoid vehicle speed jitter and achieve the damping effect. For example, if the preset time is 500 milliseconds, the vehicle speed will only change every 500 milliseconds.

On the basis of the above-mentioned vehicle speed display method of a vehicle digital instrument, the present invention correspondingly provides a vehicle speed display system of a vehicle digital instrument, comprising:

The filtering unit is used to filter the duty cycle of the pulse signal collected by the Hall sensor in the collection period;

The conversion unit is used to convert the filtered pulse signal by using the set K value pulse coefficient, and calculate and obtain the real-time vehicle speed of the current collection period;

a smoothing unit, configured to perform mean value smoothing processing on the real-time vehicle speed to obtain a smoothed vehicle speed;

The vehicle speed determination unit is configured to determine the updated vehicle speed according to whether the difference between the adjacent first smooth vehicle speed and the second smooth vehicle speed is greater than the vehicle speed update threshold; if the difference is greater than the vehicle speed update threshold, the second smooth vehicle speed is increased. Half of the above difference is used as the updated vehicle speed, otherwise, the second smoothed vehicle speed is used as the updated vehicle speed;

The updating unit is configured to refresh the updated vehicle speed every preset time, and display the updated vehicle speed.

The specific implementation manners of the filtering unit, the smoothing unit and the vehicle speed determining unit in the above system have been described in detail in the foregoing method, and will not be repeated here.

Based on the description of the above specific embodiments, the vehicle speed display method and system of the vehicle digital instrument provided by the present invention have the following advantages compared with the prior art:

First, by smoothing the mean value of the vehicle speed, the accuracy of the vehicle speed is improved and the influence of sudden changes is avoided.

Second, determine the updated vehicle speed according to whether the difference between the adjacent first smoothed vehicle speed and the second smoothed vehicle speed is greater than the vehicle speed update threshold, and if the difference is greater than the vehicle speed update threshold, add the second smoothed vehicle speed to the Half of the difference is used as the updated vehicle speed, otherwise, the second smoothed vehicle speed is used as the updated vehicle speed, which reduces the influence of vehicle speed data jitter.

Third, the calculation method is simple, the calculation speed is fast, the real-time performance is good, and the user experience is good.

Finally, it should also be noted that the terms "comprising", "comprising" or any other variation thereof used herein are intended to encompass non-exclusive inclusion such that a process, method, article or device comprising a series of elements not only Include those elements, but also other elements not expressly listed or inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprises a..." does not preclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

The present invention is not limited to the above-mentioned best embodiment. Anyone should be aware of the structural changes made under the inspiration of the present invention, and any technical solutions that are the same or similar to those of the present invention shall fall within the protection scope of the present invention. Inside.

Claims (10)

1. A vehicle speed display method of a vehicle digital instrument is characterized by comprising the following steps:

carrying out duty ratio filtering processing on pulse signals acquired by a Hall sensor in an acquisition period;

converting the filtered pulse signal by using a set K value pulse coefficient, and calculating to obtain the real-time vehicle speed of the current acquisition period;

carrying out mean value smoothing processing on the real-time vehicle speed to obtain a smooth vehicle speed;

determining an updated vehicle speed according to whether the difference value between the first smooth vehicle speed and the second smooth vehicle speed which are adjacent in the front and back is larger than a vehicle speed updating threshold; if the difference is greater than the vehicle speed updating threshold, taking the second flat pulley speed plus half of the difference as the updating vehicle speed, otherwise, taking the second flat pulley speed as the updating vehicle speed;

and refreshing the updated vehicle speed once every preset time, and displaying the updated vehicle speed.

2. The method of claim 1, wherein the duty cycle filtering process discards pulse signals with duty cycles greater than (50+ P)% and less than (50-P)% where P is a preset filtering parameter and is a natural number greater than 1.

3. The method of claim 1, wherein the mean smoothing is performed by:

taking a current real-time vehicle speed Vn and previous s real-time vehicle speeds Vn-s, Vn-s +1 and Vn-s +2 …;

the smoothing vehicle speed Vi is obtained by using the formula Vi ═ Vn-s +1+ Vn-s +2 … Vn)/s, where n is a natural number greater than 2 and s is a natural number greater than 1.

4. The method of claim 1, wherein the vehicle speed update threshold is 1 km/h.

5. The method of claim 1, wherein the predetermined time is 500 milliseconds.

6. The method of claim 1, wherein the updated vehicle speed is displayed in a numeric and pointer synchronization.

7. A vehicle speed display system for a vehicle digital instrument, comprising:

the filtering unit is used for carrying out duty ratio filtering processing on the pulse signals collected by the Hall sensor in the collection period;

the conversion unit is used for converting the filtered pulse signals by using the set K value pulse coefficient and calculating to obtain the real-time vehicle speed of the current acquisition period;

the smoothing unit is used for carrying out mean value smoothing processing on the real-time vehicle speed to obtain a smooth vehicle speed;

the vehicle speed determining unit is used for determining an updated vehicle speed according to whether the difference value between the first smooth vehicle speed and the second smooth vehicle speed which are adjacent in the front and back is larger than a vehicle speed updating threshold; if the difference is greater than the vehicle speed updating threshold, taking the second flat pulley speed plus half of the difference as the updating vehicle speed, otherwise, taking the second flat pulley speed as the updating vehicle speed;

and the updating unit is used for refreshing the updated vehicle speed once every preset time and displaying the updated vehicle speed.

8. The system of claim 7, wherein the filtering unit discards pulse signals having duty cycles greater than (50+ P)% and less than (50-P)% where P is a preset filtering parameter and is a natural number greater than 1, and updates the vehicle speed by using numbers and pointers for synchronous display.

9. The system of claim 7, wherein the vehicle speed update threshold is 1 km/h.

10. The system of claim 7, wherein the preset time is 500 milliseconds.

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