CN112881027B

CN112881027B - Method, device and system for determining automobile braking energy recovery efficiency

Info

Publication number: CN112881027B
Application number: CN201911205899.XA
Authority: CN
Inventors: 朱晓军; 郭海
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2019-11-29
Filing date: 2019-11-29
Publication date: 2023-07-11
Anticipated expiration: 2039-11-29
Also published as: CN112881027A

Abstract

The embodiment of the invention provides a method, a device and a system for determining the recovery efficiency of automobile braking energy. The method for determining the braking energy recovery efficiency of the automobile comprises the following steps: acquiring first braking state information of a test vehicle, wherein the braking state information comprises the speed of the test vehicle in a braking process, the voltage of a motor controller in the test vehicle, the current of the motor controller, the mass of the test vehicle, the acceleration of the test vehicle and the braking time of the test vehicle; and determining the braking energy recovery efficiency of the test vehicle in the braking process according to the braking state information of the test vehicle. That is, in the embodiment of the invention, the energy recovery efficiency is determined according to the voltage and the current of the motor controller and in combination with other data, so that the accuracy of the braking energy recovery efficiency of the tested vehicle in the braking process can be more accurately determined, and the accuracy of the evaluation result is improved when the vehicle is finally evaluated according to the braking energy recovery efficiency.

Description

Method, device and system for determining automobile braking energy recovery efficiency

Technical Field

The invention relates to the technical field of automobiles, in particular to a method, a device and a system for determining automobile braking energy recovery efficiency.

Background

Compared with the traditional fuel oil vehicle, the pure electric vehicle or the hybrid electric vehicle has the greatest advantages of saving energy, and recovering braking energy in the braking process, so that the energy utilization rate is improved. The recovery of braking energy refers to that the vehicle releases braking energy in the process of braking the vehicle, and the braking energy released by the vehicle is transferred into a power battery in the vehicle through a motor. Therefore, it is necessary to determine the braking energy recovery efficiency during the braking of the vehicle.

In the related art, there are mainly three methods for determining the braking energy recovery efficiency during the braking of a vehicle, including: simulation test, bench test and field test.

The inventor finds in the research process that in the related art, when determining the recovery efficiency of braking energy in the braking process of a vehicle, the determined recovery efficiency of the vehicle in the braking process has larger deviation from the actual recovery efficiency of the vehicle, so that the accuracy of the determined recovery efficiency of the vehicle in the braking process is lower, and finally, the evaluation result is influenced when the vehicle is evaluated according to the recovery efficiency of the braking energy.

Disclosure of Invention

The embodiment of the invention provides a method, a device and a system for determining the recovery efficiency of automobile braking energy, which can improve the accuracy of determining the recovery efficiency of the braking energy of a test vehicle in the braking process.

In a first aspect, there is provided an automobile brake energy recovery efficiency determining method including:

acquiring first braking state information of a test vehicle, wherein the first braking state information comprises the speed of the test vehicle in a braking process, the voltage of a motor controller of the test vehicle, the current of the motor controller, the mass of the test vehicle, the acceleration of the test vehicle and the braking time of the test vehicle;

and determining the braking energy recovery efficiency of the test vehicle in the braking process according to the first braking state information of the test vehicle.

Optionally, the first braking state information further includes: the wheel rotational speed of the test vehicle during braking and the rotational inertia of the wheels of the test vehicle.

Optionally, the determining the braking energy recovery efficiency of the test vehicle in the braking process according to the first braking state information of the test vehicle includes:

Determining feedback electric energy generated by the test vehicle in the braking process according to the voltage of the motor controller in the test vehicle and the current of the motor controller;

determining braking kinetic energy of the test vehicle in a braking process according to the vehicle speed, the acceleration of the test vehicle, the mass of the test vehicle and the braking time of the test vehicle;

determining the rotational kinetic energy of the wheels of the test vehicle in the braking process according to the rotational inertia of the wheels of the test vehicle and the rotational speed of the wheels;

determining resistance energy consumed by resistance of the test vehicle in a braking process according to the vehicle speed;

and determining the braking energy recovery efficiency of the test vehicle in the braking process according to the feedback electric energy, the braking kinetic energy, the rotational kinetic energy and the resistance energy.

Optionally, the determining feedback electric energy generated by the test vehicle in the braking process according to the voltage of the motor controller and the current of the motor controller in the test vehicle includes:

screening the current of the motor controller according to preset conditions to obtain screened current after screening;

determining feedback electric energy generated by the test vehicle in the braking process according to the voltage of the motor controller in the test vehicle and the screening current;

The determining braking kinetic energy of the test vehicle in the braking process according to the vehicle speed, the acceleration of the test vehicle, the mass of the test vehicle and the braking time of the test vehicle comprises the following steps:

determining an initial speed of the test vehicle when braking is started and a final speed of the test vehicle after braking is finished according to the vehicle speed, the acceleration of the test vehicle and the braking time of the test vehicle;

determining braking kinetic energy of the test vehicle in the braking process according to the initial speed of the test vehicle when braking is started, the final speed of the test vehicle after braking is finished and the mass of the test vehicle;

the determining the rotational kinetic energy of the wheels of the test vehicle in the braking process according to the rotational inertia of the wheels of the test vehicle and the rotational speed of the wheels comprises the following steps:

performing first filtering treatment on the wheel rotating speed to obtain a filtered wheel rotating speed after first filtering;

determining the kinetic energy of the wheels of the test vehicle in the braking process according to the rotational inertia of the wheels of the test vehicle and the rotational speed of the filtered wheels;

the method for determining the resistance energy consumed by the resistance of the test vehicle in the braking process according to the vehicle speed comprises the following steps:

Performing second filtering processing on the vehicle speed to obtain a filtered vehicle speed after second filtering;

acquiring a sliding coefficient of the test vehicle in a braking process;

determining resistance energy consumed by resistance of the test vehicle in a braking process according to the filter vehicle speed and the sliding coefficient;

optionally, the determining feedback electric energy generated by the test vehicle in the braking process according to the voltage of the motor controller and the screening current includes:

E _{returning to} ＝∫UIdt

Wherein E is _{Returning to} The feedback electric energy generated by the test vehicle in the braking process is represented, U represents the voltage of the motor controller, I represents the screening current, and t represents the braking time of the test vehicle;

the determining the braking kinetic energy of the test vehicle in the braking process according to the initial speed of the test vehicle when starting braking, the final speed of the test vehicle after finishing braking and the mass of the test vehicle comprises the following steps:

wherein E is _{Manufacturing process} Representing braking kinetic energy of the test vehicle in a braking process, and m represents mass of the test vehicle; v1 represents the initial speed of the test vehicle when starting braking, v2 represents the final speed of the test vehicle after finishing braking;

According to the rotational inertia and the filter wheel rotational speed, determining rotational kinetic energy of the wheels of the test vehicle in the braking process comprises the following steps:

wherein E is _Rotation The rotational kinetic energy of the wheels of the test vehicle in the braking process is represented, J represents the rotational inertia, and n represents the rotational speed of the filtered wheels;

and determining the resistance energy consumed by the resistance of the test vehicle in the braking process according to the filter vehicle speed and the sliding coefficient, wherein the method comprises the following steps of:

E _{resistance resistor} ＝∫3.6×10 ⁶ ×v×(A+Bv+Cv ² )dt

Wherein E is _{Resistance resistor} Resistance energy representing resistance consumption of the test vehicle in a braking process, and v representing the filtered vehicle speed; t represents the braking time of the test vehicle, A, B and C represent different sliding coefficients of the test vehicle respectively;

the determining the braking energy recovery efficiency of the test vehicle in the braking process according to the feedback electric energy, the braking kinetic energy, the rotational kinetic energy and the resistance energy comprises the following steps:

or (b)

Where η represents the braking energy recovery efficiency of the test vehicle during braking.

Optionally, before the acquiring the first braking state information of the test vehicle, the method for determining the braking energy recovery efficiency of the automobile further includes:

Acquiring state information of the test vehicle under a preset working condition, wherein the preset working condition refers to information which is required to be determined in advance before the test vehicle brakes;

and taking the state information of the test vehicle under the preset working condition as the braking state information of the test vehicle.

Optionally, after determining the braking energy recovery efficiency of the test vehicle during braking, the method for determining the braking energy recovery efficiency of the vehicle further includes:

evaluating the performance of the test vehicle according to the braking energy recovery efficiency of the test vehicle in the braking process;

the evaluating the performance of the test vehicle according to the brake energy recovery efficiency of the test vehicle in the brake process comprises the following steps:

acquiring the preset braking energy recovery efficiency of the test vehicle;

and evaluating the performance of the test vehicle according to the preset braking energy recovery efficiency and the braking energy recovery efficiency of the test vehicle in the braking process.

In a second aspect, there is provided an automobile brake energy recovery efficiency determining apparatus including:

a first obtaining module, configured to obtain first braking state information of a test vehicle, where the braking state information includes a vehicle speed of the test vehicle during braking, a voltage of a motor controller of the test vehicle, a current of the motor controller, a mass of the test vehicle, an acceleration of the test vehicle, and a braking time of the test vehicle;

And the determining module is used for determining the braking energy recovery efficiency of the test vehicle in the braking process according to the first braking state information of the test vehicle.

Optionally, the determining module includes:

the first determining unit is used for determining feedback electric energy generated by the test vehicle in the braking process according to the voltage of the motor controller in the test vehicle and the current of the motor controller;

a second determining unit, configured to determine braking kinetic energy of the test vehicle during a braking process according to the vehicle speed, the acceleration of the test vehicle, the mass of the test vehicle, and the braking time of the test vehicle;

a third determining unit, configured to determine rotational kinetic energy of wheels of the test vehicle during braking according to rotational inertia of the wheels of the test vehicle and the vehicle speed;

a fourth determining unit, configured to determine resistance energy consumed by resistance of the test vehicle in a braking process according to a vehicle speed;

and the fifth determining unit is used for determining the braking energy recovery efficiency of the test vehicle in the braking process according to the feedback electric energy, the braking kinetic energy, the rotating kinetic energy and the resistance energy.

Optionally, the first determining unit includes:

the screening subunit is used for screening the current of the motor controller according to preset conditions to obtain screened current after screening;

the first determining subunit is used for determining feedback electric energy generated by the test vehicle in the braking process according to the voltage of the motor controller in the test vehicle and the screening current;

the second determination unit includes:

the second determining subunit is used for determining the initial speed of the test vehicle when starting braking and the final speed of the test vehicle after finishing braking according to the vehicle speed, the acceleration of the test vehicle and the braking time of the test vehicle;

a third determination subunit, configured to determine braking kinetic energy of the test vehicle in a braking process according to an initial speed of the test vehicle when braking is started, a final speed of the test vehicle after braking is ended, and a mass of the test vehicle;

the third determination unit includes:

the first filtering subunit is used for carrying out first filtering processing on the wheel rotating speed to obtain a filtered wheel rotating speed after the first filtering;

a fourth determination subunit, configured to determine rotational kinetic energy of the wheels of the test vehicle during braking according to rotational inertia of the wheels of the test vehicle and the filtered wheel rotational speed;

The fourth determination unit includes:

the second filtering subunit is used for carrying out second filtering processing on the vehicle speed to obtain a filtered vehicle speed after the second filtering;

the acquisition subunit is used for acquiring the sliding coefficient of the test vehicle in the braking process;

and the fifth determination subunit is used for determining the resistance energy consumed by the resistance of the test vehicle in the braking process according to the filter vehicle speed and the sliding coefficient.

Optionally, the first determining subunit is further configured to:

E _{returning to} ＝∫UIdt

the third determination subunit is further configured to:

the fourth determination subunit is further configured to:

The fifth determination subunit is further configured to:

E _{resistance resistor} ＝∫3.6×10 ⁶ ×v×(A+Bv+Cv ² )dt

the fifth determination unit is configured to:

or (b)

Optionally, the device for determining the braking energy recovery efficiency of the automobile further comprises:

the second acquisition module is used for acquiring state information of the test vehicle under a preset working condition, wherein the preset working condition refers to information, which is required to be determined in advance, of the test vehicle before braking;

the evaluation module is used for evaluating the performance of the test vehicle according to the braking energy recovery efficiency of the test vehicle in the braking process;

the evaluation module is used for:

acquiring the preset braking energy recovery efficiency of the test vehicle;

In a third aspect, there is provided an automobile brake energy recovery efficiency determining apparatus including:

a processor;

a memory for storing processor-executable instructions;

wherein the processor is configured to perform the steps of any of the methods of the first aspect above.

In a fourth aspect, there is provided a computer readable storage medium having stored thereon instructions which when executed by a processor perform the steps of the method of any of the first aspects described above.

In a fifth aspect, an automobile braking energy recovery efficiency determining system is provided, the automobile braking energy recovery efficiency determining system includes an upper computer, a data collector and a test vehicle;

the upper computer is used for determining the braking energy recovery efficiency of the test vehicle in the braking process according to the first braking state information acquired by the data acquisition device.

The technical scheme provided by the invention has the beneficial effects that at least the following steps are included:

in the embodiment of the invention, the braking state information of the test vehicle is obtained, wherein the braking state information can comprise the speed of the test vehicle in the braking process, the voltage of a motor controller of the test vehicle, the current of the motor controller, the mass of the test vehicle, the acceleration of the test vehicle and the braking time of the test vehicle, and the braking energy recovery efficiency of the test vehicle in the braking process is determined according to the braking state information of the test vehicle. According to the embodiment of the invention, the accuracy of the braking energy recovery efficiency of the test vehicle in the braking process can be more accurately determined by acquiring the voltage and the current of the motor controller in the braking process of the test vehicle and determining the energy recovery efficiency according to the voltage and the current of the motor controller and combining other data, and further, the accuracy of the evaluation result is improved when the vehicle is evaluated according to the braking energy recovery efficiency.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments of the present invention will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a power output path of a power cell in a test vehicle according to an embodiment of the present invention;

FIG. 2 is a flowchart of a method for determining the recovery efficiency of braking energy of an automobile according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a NEDC cycle provided by an embodiment of the present invention;

FIG. 4 is a test plot taken when the test vehicle is traveling in accordance with the NEDC cycle of FIG. 3;

FIG. 5 is a schematic diagram of an apparatus for determining an efficiency of braking energy recovery of an automobile according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of an apparatus for determining an efficiency of braking energy recovery of an automobile according to an embodiment of the present invention;

fig. 7 is a schematic diagram of an automobile braking energy recovery efficiency determining system according to an embodiment of the present invention.

Reference numerals:

1: an upper computer; 2: a data collector; 3: testing the vehicle; 4: a vehicle diagnostic interface.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Before explaining the method for determining the braking energy recovery efficiency of the automobile provided by the embodiment of the invention, specific explanation is made on the application scene of the embodiment of the invention: in the related art, when determining the braking energy recovery efficiency of an automobile, state information of a test vehicle in a braking process is acquired first, and then the braking energy recovery efficiency of the test vehicle in the braking process is determined according to the state information of the test vehicle in the braking process. The state information comprises a vehicle speed of the test vehicle in a braking process, voltages at two ends of a power battery in the test vehicle, currents at two ends of the power battery, a mass of the test vehicle, acceleration of the test vehicle and braking time of the test vehicle.

As shown in fig. 1, the power in the power battery in the test vehicle can be output through three paths, the first: the power from the power cell is transmitted via a DC/DC converter to electrical accessories in the test vehicle. And a second strip: the power of the power battery is transmitted to the motor through the motor controller so that the motor drives the test vehicle. Third strip: the electric power of the power battery is transmitted to the vehicle-mounted air conditioner through the A/C converter. The electric appliance accessory refers to an electric appliance for testing low voltage such as Bluetooth, sound equipment and radio in a vehicle, and the DC/DC converter refers to a converter for converting a fixed direct current voltage into a variable direct current voltage. DC is Direct Current, namely Direct Current, and A/C is Air Condition, namely Air conditioning.

In the braking process of the test vehicle, since the power battery supplies power to the electric accessories and the vehicle-mounted air conditioner in addition to the motor, it may be inaccurate to acquire the voltage and current across the power battery to determine the braking energy recovery efficiency. In addition, during braking of the test vehicle, kinetic energy of wheels of the test vehicle due to rotation may also be converted into electric energy to be stored in the power battery, and in the related art, a part of the energy is not considered, and thus, the braking energy recovery efficiency determined according to the related art may be inaccurate. The method for determining the automobile braking energy recovery efficiency is applied to the scene.

Fig. 2 is a flowchart of a method for determining an automobile braking energy recovery efficiency according to an embodiment of the present invention. As shown in fig. 1, the method comprises the steps of:

step 101: first brake state information of a test vehicle is acquired.

The first braking state information comprises a vehicle speed of the test vehicle in a braking process, a voltage of a motor controller of the test vehicle, a current of the motor controller, a mass of the test vehicle, an acceleration of the test vehicle and a braking time of the test vehicle.

It should be noted that, since the acceleration of the test vehicle during braking is obtained, the value of the acceleration may be a negative value.

In addition, the braking state information of the test vehicle may be stored in advance by a worker, or may be obtained in real time when the test vehicle is tested, which is not limited in the embodiment of the present invention.

It should be noted that, in the embodiment of the present invention, the power battery is connected to the motor controller, and the motor controller is connected to the motor. In the braking process of the test vehicle, the motor can generate electric power, and the electric power is transmitted to the power battery through the motor controller, so that the voltage of the motor controller and the current of the motor controller are obtained, and the electric energy input into the power battery in the braking process of the test vehicle can be accurately determined.

The motor controlled by the motor controller is a motor for driving the test vehicle to move, namely, the motor controller controls a driving motor in the test vehicle. When the test vehicle is a pure electric vehicle, the test vehicle comprises a driving motor, and the motor controlled by the motor controller is the driving motor. When the test vehicle is a hybrid vehicle, the test vehicle includes a drive motor and a generator, and at this time, the motor controlled by the motor controller is the drive motor and the generator. The generator may be a BSG (Belt Driven Starter Generator ) motor.

In addition, during testing of the test vehicle, the acceleration of the test vehicle may be determined based on the depth of braking of the brake pedal in the test vehicle. The braking depth of the brake pedal refers to the distance between the current position of the brake pedal and the initial position of the brake pedal. The initial position of the brake pedal refers to a position when the brake pedal is not depressed, and the current position of the brake pedal refers to a position when the brake pedal is depressed.

Specifically, the acceleration of the test vehicle may be determined according to the correspondence between the braking depth of the brake pedal and the acceleration. The correspondence between the braking depth and the acceleration of the brake pedal may be: when the braking depth of the brake pedal is in a first range, the first range corresponds to one acceleration value, and when the braking depth of the brake pedal is in a second range, the second range corresponds to the other acceleration value.

For example, table 1 shows a correspondence relationship between a braking depth and an acceleration of a brake pedal according to an embodiment of the present invention. As shown in Table 1, when the braking depth of the brake pedal is between 0.5 and 0.8cm, the corresponding acceleration value is-0.85 m/s ² . When the braking depth of the brake pedal is between 0.8cm and 1cm, the corresponding acceleration value is-1 m/s ² 。

TABLE 1

Depth of braking range (cm) of brake pedal	Testing acceleration of vehicle (m/s ² )
		0.5-0.8	-0.85
0.8-1	-1

In addition, in the embodiment of the present invention, the mass of the test vehicle refers to the sum of the preparation mass of the test vehicle and 100 kg, that is, the mass of the test vehicle is equal to the preparation mass of the test vehicle plus 100 kg. The quality of the test vehicle is the weight of the test vehicle after the test vehicle is completely assembled (such as spare tire, tools and the like are completely assembled) according to the technical conditions of delivery.

In addition, in order to facilitate comparison of the method for determining the braking energy recovery efficiency of the automobile provided by the embodiment of the invention, before step 101, the method for determining the braking energy recovery efficiency of the automobile may further include: acquiring state information of the test vehicle under a preset working condition, wherein the preset working condition refers to information, which is required to be predetermined, of the test vehicle in a braking process. And taking the state information of the test vehicle under the preset working condition as the braking state information of the test vehicle. The status information may include, among other things, a vehicle speed of the test vehicle during braking, a voltage of a motor controller of the test vehicle, a current of the motor controller, a mass of the test vehicle, an acceleration of the test vehicle, and a braking time of the test vehicle.

The implementation of obtaining the state information of the test vehicle under the preset working condition may be: the test vehicle runs according to a preset working condition, and state information of the test vehicle is collected in real time in the running process.

Furthermore, the test vehicle can run on a standard test site according to preset working conditions, and state information of the test vehicle is collected in real time in the running process.

Of course, after the test vehicle runs according to the preset working condition, the acquired state information of the test vehicle can be stored, and when the braking energy recovery efficiency of the automobile needs to be determined, the stored state information can be directly acquired.

It should be noted that the preset working condition may be defined according to a standard test cycle specified by an industry standard or a national standard. For example, the predetermined operating conditions may be in accordance with NEDC (New Europe Driving Cycle, NEDC, new european automobile regulation cycle conditions). Or in accordance with WLTC (world Light Test Cycle). Of course, the preset working conditions may also be according to other working conditions, and the embodiment of the present invention is not limited herein.

For example, fig. 3 is a schematic diagram of NEDC cycle provided in an embodiment of the present invention. As shown in fig. 3, the preset operating conditions are defined by cycling NEDC. Of these, NEDC is consistent with the test cycle specified in GB 18352.5. In fig. 3, the cycle can be divided into two major parts, the first part (1) and the second part (2). Wherein (1) represents a urban cycle, (2) represents a suburban cycle, and (3) represents a subunit of the urban cycle. As shown in fig. 3, the vehicle undergoes acceleration, uniform velocity, deceleration, re-acceleration, re-uniform velocity, re-deceleration throughout the cycle, thus continuously cycling. In addition, as can be seen from fig. 3, in the NEDC cycle, there are 8 braking processes of the vehicle, that is, 8 deceleration processes of the vehicle, respectively: (1) The speed of the vehicle is 15 km/h-0 km/h, and the acceleration is-0.83 m/s ² . (2) The speed of the vehicle is 32 km/h-0 km/h, and the acceleration is-0.81 m/s ² . (3) The speed of the vehicle is 50 km/h-35 km/h, and the acceleration is-0.52 m/s ² . (4) The speed of the vehicle is 35 km/h-0 km/h, and the acceleration is-0.97 m/s ² . (5) The speed of the vehicle is 70 km/h-50 km/h, and the acceleration is-0.69 m/s ² . (6) The speed of the vehicle is 120 km/h-80 km/h, and the acceleration is-0.69 m/s ² . (7) The speed of the vehicle is 80 km/h-50 km/h, and the acceleration is-1.04 m/s ² . (8) The speed of the vehicle is 50 km/h-0 km/h, and the acceleration is-1.39 m/s ² 。

Because the braking process is more, the 8 braking processes can be combined and simplified according to the continuity and the acceleration in the braking process, and the following 3 types are obtained: (1) The speed of the vehicle is 30 km/h-10 km/h, and the acceleration is-0.8 m/s ² . (2) The speed of the vehicle is 80 km/h-10 km/h, and the acceleration is-1.2 m/s ² . (3) The speed of the vehicle is 120 km/h-10 km/h, and the acceleration is-0.7 m/s ² . That is, the preset conditions may be the above 3 braking processes.

In the embodiment of the invention, the acceleration may also be referred to as a braking strength.

In addition, since the SOC (state of charge) of the power battery of the test vehicle may affect the braking energy recovery efficiency, in the embodiment of the present invention, the first braking state information of the test vehicle may be obtained by determining that the power battery is in a state of different SOCs under the condition that the test vehicle is in accordance with the preset working condition. The SOC of the power battery refers to a state of charge, and may also be referred to as a remaining charge, and indicates a capability of the power battery to continue to operate.

In addition, in order to complete the whole testing process during the testing process, in some embodiments, the test vehicle may also perform the testing according to different gears. For example, the test vehicle may be in a driving gear, i.e., a forward gear, during braking, at which time braking is performed. The test vehicle may also be in neutral during braking, when braking is being performed.

For example, according to 3 vehicle speeds and 3 accelerations after the simplified combination in FIG. 3, i.e., the vehicle speed is 30km/h to 10km/h, the acceleration is-0.8 m/s ² The method comprises the steps of carrying out a first treatment on the surface of the The speed of the vehicle is 80 km/h-10 km/h, and the acceleration is-1.2 m/s ² The method comprises the steps of carrying out a first treatment on the surface of the The speed of the vehicle is 120 km/h-10 km/h, and the acceleration is-0.7 m/s ² . The gears of the test vehicle during braking may be forward and neutral. The SOC of the power cells in the test vehicle may be 90%, 60% and 30%, respectively.

At this time, when the power battery in the test vehicle is 90%, the running can be performed according to the following 6 cases:

(1) The SOC of the power battery of the test vehicle is 90 plus or minus 5 percent, the test vehicle is accelerated to (30 plus or minus 2) km/h, after the test vehicle stably runs for 5 seconds, the test vehicle is firstly put into a neutral position, and then the brake pedal is stepped, so that the acceleration of the whole vehicle is controlled to be- (0.8 plus or minus 0.05) m/s ² Until the speed of the test vehicle is zero.

(2) The SOC of the power battery of the test vehicle is 90% +/-5%, the test vehicle is accelerated to 30+/-2 km/h, after the test vehicle runs stably for 5 seconds, the test vehicle is firstly put into forward gear, and then the brake pedal is stepped, so that the acceleration of the whole vehicle is controlled to be- (0.8+/-0.05) m/s ² Until the speed of the test vehicle is zero.

(3) The SOC of the power battery of the test vehicle is 90% +/-5%, the test vehicle is accelerated to 80+/-2 km/h, after the test vehicle stably runs for 5s, the test vehicle is firstly in neutral position, and then the brake pedal is depressed, so that the acceleration of the whole vehicle is controlled to be- (1.2+/-0.05) m/s ² Until the speed of the test vehicle is zero.

(4) The SOC of the power battery of the test vehicle is 90% +/-5%, the test vehicle is accelerated to 80+/-2 km/h, after the test vehicle stably runs for 5s, the test vehicle is firstly put into forward gear, and then the brake pedal is stepped, so that the acceleration of the whole vehicle is controlled to be- (1.2+/-0.05) m/s ² Until the speed of the test vehicle is zero.

(5) The SOC of the power battery of the test vehicle is 90 percent plus or minus 5 percent, the test vehicle is accelerated to 120 percent plus or minus 2km/h, after stable running for 5 seconds, the test vehicle is firstly put in neutral position, and then the brake pedal is stepped, so that the whole vehicle is realizedAcceleration is controlled to be- (0.7+/-0.05) m/s ² Until the speed of the test vehicle is zero.

(6) The SOC of the power battery of the test vehicle is 90% +/-5%, the test vehicle is accelerated to 120+/-2 km/h, after the test vehicle runs stably for 5s, the test vehicle is firstly put into forward gear, and then the brake pedal is stepped, so that the acceleration of the whole vehicle is controlled to be- (0.7+/-0.05) m/s ² Until the speed of the test vehicle is zero.

The test vehicle can run according to the condition in the above 6 when the power battery is 60% and 30% respectively, and the first brake state information of the test vehicle is obtained in the running process of the test vehicle.

When the SOC of the power battery of the test vehicle is 90%, the vehicle travels according to the above 6 cases, and 6 pieces of state information of the test vehicle can be obtained.

In addition, during the test of the test vehicle, the preset conditions may be other conditions, for example, the SOC of the power battery of the test vehicle is 20%, 40%, 60% and 80%, respectively. The speed of the vehicle can be 40 km/h-20 km/h, and the acceleration is-0.85 m/s ² The method comprises the steps of carrying out a first treatment on the surface of the The speed of the vehicle is 90 km/h-20 km/h, and the acceleration is-1.4 m/s ² The method comprises the steps of carrying out a first treatment on the surface of the The speed of the vehicle is 130 km/h-20 km/h, and the acceleration is-0.6 m/s ² . The gear of the test vehicle during braking may be neutral. The embodiments of the present invention are not limited herein.

Step 102: and determining the braking energy recovery efficiency of the test vehicle in the braking process according to the first braking state information of the test vehicle.

Wherein, in some embodiments, the first braking state information may further comprise a wheel rotational speed of the test vehicle during braking and a moment of inertia of the wheel of the test vehicle

It should be noted that, before the test vehicle is tested, the moment of inertia of the wheels of the test vehicle may be obtained through a moment of inertia experiment. The moment of inertia of the wheels of the test vehicle can also be obtained through calculation, and the moment of inertia can be specifically shown as the following formula:

in the above formula, J is the moment of inertia of the wheels of the test vehicle, R ₁ To test the inside diameter of the wheels of a vehicle, R ₂ To test the outer diameter of the wheels of the vehicle.

At this time, the implementation manner of step 102 may be: determining feedback electric energy generated by the test vehicle in the braking process according to the voltage of the motor controller and the current of the motor controller in the test vehicle, wherein the feedback electric energy refers to electric energy input to a power battery in the test vehicle in the braking process of the test vehicle; determining braking kinetic energy of the test vehicle in the braking process according to the vehicle speed, the acceleration of the test vehicle, the mass of the test vehicle and the braking time of the test vehicle, wherein the braking kinetic energy refers to energy generated by the test vehicle in the braking process; determining the rotational kinetic energy of the wheels of the test vehicle in the braking process according to the rotational inertia and the vehicle speed of the wheels of the test vehicle; determining resistance energy consumed by resistance of the test vehicle in the braking process according to the vehicle speed; and determining the braking energy recovery efficiency of the test vehicle in the braking process according to the feedback electric energy, the braking kinetic energy, the rotational kinetic energy and the resistance energy.

The implementation manner of determining feedback electric energy generated by the test vehicle in the braking process according to the voltage of the motor controller and the current of the motor controller in the test vehicle can be as follows: screening the current of the motor controller according to preset conditions to obtain screened current after screening; and determining feedback electric energy generated by the test vehicle in the braking process according to the voltage and screening current of the motor controller in the test vehicle.

It should be noted that, in the braking process of the test vehicle, the braking system in the test vehicle charges the power battery, the power battery also supplies power to the motor, the electrical accessories and the like in the test vehicle, and, because the motor controller is connected with the power battery, when the braking system charges the power battery, current flows to the power battery through the motor controller, and when the power battery supplies power to the motor, the electrical accessories and the like in the test vehicle, the current also flows through the motor controller. Since the direction of the current is opposite when the power battery is charged and the power battery is supplied to the outside, and the brake system in the test vehicle charges the power battery in the process of testing the vehicle braking, in order to accurately determine the recovery efficiency, the current when the brake system charges the power battery in the process of braking needs to be determined, and the current when the power battery is supplied to the outside does not need to be determined. However, since the current direction of charging the power battery is opposite to the current direction of supplying power to the outside from the power battery and the current passes through the motor controller, the current of the motor controller needs to be screened.

When the current direction of the power battery is positive, the current direction of the power battery is negative, and the current value of the motor controller in the positive direction is positive, and the current value in the negative direction is negative during braking. In this case, in order to determine the current to charge the power battery, the preset condition may be that the current value is less than zero, i.e., the current value of the motor controller is eliminated to be greater than zero, and only the current value of the motor controller is acquired to be less than zero.

For example, fig. 4 is a test graph obtained when the test vehicle runs in accordance with the NEDC cycle in fig. 3. As shown in fig. 4, the test curve of the current of the motor controller is divided into 4 parts, namely a 1 st part, a 2 nd part, a 3 rd part and a 4 th part, wherein the current value of the 1 st part, the current value of the 2 nd part and the current value of the 4 th part are all larger than zero, and the current value of the 3 rd part is smaller than zero. And (3) eliminating the current value of the 1 st part, the current value of the 2 nd part and the current value of the 4 th part according to the preset condition that the current value is smaller than zero, and only keeping the current value of the 3 rd part. Also, as shown in fig. 4, the voltage of the motor controller is also continuously variable.

When the current direction of the power battery supplying power to the outside is specified to be negative, the current direction of charging the power battery is specified to be positive, and at this time, the current value of the motor controller in the positive direction is specified to be positive and the current value in the negative direction is specified to be negative in the braking process. In this case, in order to determine the current to charge the power battery, the preset condition may be that the current value is greater than 0, that is, the current value of the motor controller is less than 0 is eliminated, and only the current value of the motor controller is greater than 0 is acquired.

The implementation manner of determining the feedback electric energy generated by the test vehicle in the braking process according to the voltage of the motor controller in the test vehicle and the screened current can be shown as follows:

E _{returning to} ＝∫UIdt

In the above formula, U represents the voltage of the motor controller during the braking process of the test vehicle; i represents screening current of a tested vehicle after screening according to preset conditions in a braking process of the tested vehicle; e (E) _{Returning to} The feedback electric energy generated by the test vehicle in the braking process is represented, and t represents the braking time of the test vehicle.

In addition, according to the vehicle speed, the acceleration of the test vehicle, the mass of the test vehicle and the braking time of the test vehicle, the implementation manner of determining the braking kinetic energy of the test vehicle in the braking process can be as follows: determining the initial speed of the test vehicle when starting braking and the final speed of the test vehicle after finishing braking according to the vehicle speed, the acceleration of the test vehicle and the braking time of the test vehicle; and determining the braking kinetic energy of the test vehicle in the braking process according to the initial speed of the test vehicle at the beginning of braking, the final speed of the test vehicle at the end of braking and the mass of the test vehicle.

According to the vehicle speed, the acceleration of the test vehicle and the braking time of the test vehicle, the implementation manner of determining the initial speed of the test vehicle when starting braking and the final speed of the test vehicle after finishing braking can be as follows: taking an initial speed value in the vehicle speed as an initial speed of the test vehicle when starting braking; and determining the final speed of the test vehicle after the braking is finished according to the initial speed of the test vehicle at the beginning of the braking, the acceleration of the test vehicle and the braking time of the test vehicle.

In some embodiments, the implementation of determining the final speed of the test vehicle after the end of braking based on the initial speed of the test vehicle at the start of braking, the acceleration of the test vehicle, and the braking time of the test vehicle may be as follows:

v ₂ ＝v ₁ +at

in the above, v ₁ Represents the initial speed of the test vehicle at the start of braking, a represents the acceleration of the test vehicle, v ₂ The final speed of the test vehicle after the braking is completed is indicated, and t indicates the braking time.

In some embodiments, the implementation of determining the braking kinetic energy of the test vehicle during braking according to the initial speed of the test vehicle at the beginning of braking, the final speed of the test vehicle after the end of braking, and the mass of the test vehicle may be as follows:

In the above, E _{Manufacturing process} Representing the braking kinetic energy of the test vehicle during braking; m represents the mass of the test vehicle, which can be 100kg plus the servicing mass of the test vehicle; v ₁ Representing an initial speed of the test vehicle at the start of braking; v ₂ Indicating the final speed of the test vehicle after braking is completed.

In addition, according to the rotational inertia and the rotational speed of the wheels of the test vehicle, the implementation manner of determining the rotational kinetic energy of the wheels of the test vehicle in the braking process can be as follows: performing first filtering treatment on the wheel rotation speed to obtain a filtered wheel rotation speed after the first filtering; and determining the rotational kinetic energy of the wheels of the test vehicle in the braking process according to the rotational inertia of the wheels of the test vehicle and the rotational speed of the filtered wheels.

In the process of braking a test vehicle, when the wheel rotation speed of the test vehicle is acquired, the acquired test vehicle is subjected to deviation due to signal interference or influence of sampling frequency, and in order to avoid the situation, the wheel rotation speed of the test vehicle in the braking process is subjected to first filtering processing to obtain the filtered wheel rotation speed after the first filtering. The first filtering process may be digital filtering of the wheel speed of the test vehicle during braking. Of course, the first filtering process may also perform other filtering on the wheel rotation speed, such as kalman filtering, and the embodiment of the present invention is not limited to the first filtering process.

The implementation manner of determining the kinetic energy of the wheel of the test vehicle during braking according to the rotational inertia of the wheel of the test vehicle and the wheel rotational speed after the first filtering can be shown as follows:

in the above, E _Rotation The rotational kinetic energy of the wheels of the test vehicle during braking is represented, J represents the rotational inertia of the wheels of the test vehicle, and n represents the filtered wheel speed after the first filtering.

According to the vehicle speed, the implementation mode for determining the resistance energy consumed by the resistance of the test vehicle in the braking process can be as follows: performing second filtering processing on the vehicle speed to obtain a filtered vehicle speed after the second filtering; acquiring a sliding coefficient of a test vehicle in a braking process; and determining the resistance energy consumed by the resistance of the test vehicle in the braking process according to the filtered vehicle speed and the sliding coefficient.

In the process of braking the test vehicle, when the speed of the test vehicle is acquired, the acquired test vehicle is subjected to deviation due to signal interference or influence of sampling frequency, and in order to avoid the situation, the speed of the test vehicle in the braking process is subjected to second filtering processing, so that the filtered speed after the second filtering is obtained. The second filtering process may be digital filtering of the vehicle speed of the test vehicle during braking. Of course, the second filtering process may also perform other filtering on the vehicle speed, such as kalman filtering, and the embodiment of the present invention does not limit the second filtering process.

In some embodiments, based on the filtered vehicle speed, the slip coefficient, the implementation of determining the energy consumed by the test vehicle in terms of resistance during braking may be as follows:

E _{resistance resistor} ＝∫3.6×10 ⁶ ×v×(A+Bv+Cv ² )dt

In the above, E _{Resistance resistor} Representing resistance energy to test the vehicle's resistance consumption during braking; v represents the filtered vehicle speed after the second filtering; t represents the braking time of the test vehicle, A, B and C represent the different coasting coefficients of the test vehicle, respectively.

In addition, according to the feedback electric energy, the braking kinetic energy, the rotational kinetic energy and the resistance energy, the implementation mode for determining the braking energy recovery efficiency of the test vehicle in the braking process can be shown as follows:

in the above formula, eta represents the braking energy recovery efficiency of the test vehicle in the braking process; e (E) _{Returning to} Representing feedback electrical energy generated during a test vehicle braking process; e (E) _{Manufacturing process} Representing the braking kinetic energy of the test vehicle during braking; e (E) _Rotation Representing the kinetic energy of the wheels of the test vehicle during braking; e (E) _{Resistance resistor} Representing the energy expended to test the vehicle's resistance during braking.

Wherein the above formula can also be expressed as:

in the above formula, U represents the voltage of the motor controller during the test of the braking process of the vehicle; i represents the current of the motor controller after screening according to preset conditions in the braking process of the test vehicle; t represents the braking time of the test vehicle; m represents the mass of the test vehicle, which can be 100 kg added to the servicing mass of the test vehicle; v ₁ Representing an initial speed of the test vehicle at the start of braking; v ₂ Indicating the final speed of the test vehicle after braking is finished; j represents the moment of inertia of the wheels of the test vehicle and n represents the wheel speed of the test vehicle during braking.

When determining the braking energy recovery efficiency of the test vehicle during braking according to the above formula, if the test vehicle includes a plurality of motors, each motor is connected with a motor controller, a plurality of voltages and a plurality of currents at two ends of the plurality of motor controllers are obtained, at this time, the voltages and the currents at two ends of each motor controller can be brought into the above formula, one braking energy recovery efficiency is determined, and then each braking energy recovery efficiency is added to obtain one total braking energy recovery efficiency, and the total braking energy recovery efficiency is used as the braking energy recovery efficiency of the test vehicle during braking.

For example, the test vehicle includes a first motor, a second motor and a third motor, the first motor is connected with the first motor controller, the second motor is connected with the second motor controller, the third motor is connected with the third motor controller, then the voltage and the current of the first motor controller can be obtained, the voltage and the current of the two ends of the second motor and the voltage and the current of the two ends of the third motor can be brought into the above formula for obtaining the braking energy recovery efficiency, at this time, the first recovery efficiency can be obtained, the voltage and the current of the second motor controller can be substituted into the above formula for obtaining the braking energy recovery efficiency, the second recovery efficiency can be obtained, the voltage and the current of the third motor controller can be brought into the above formula for obtaining the braking energy recovery efficiency, the third recovery efficiency can be obtained, and the sum obtained by adding the first recovery efficiency, the second recovery efficiency and the third recovery efficiency can be used as the braking energy recovery efficiency of the test vehicle in the braking process.

Additionally, to evaluate the test vehicle, in some embodiments, after determining the braking energy recovery efficiency of the test vehicle during braking, the vehicle braking energy recovery efficiency determination method may further include: and evaluating the performance of the test vehicle according to the braking energy recovery efficiency of the test vehicle in the braking process.

The implementation mode for evaluating the performance of the test vehicle according to the braking energy recovery efficiency of the test vehicle in the braking process can be as follows: the method comprises the steps of obtaining preset braking energy recovery efficiency of a test vehicle, and evaluating the performance of the test vehicle according to the preset braking energy recovery efficiency and the braking energy recovery efficiency of the test vehicle in the braking process.

The implementation manner for evaluating the performance of the test vehicle according to the preset braking energy recovery efficiency and the braking energy recovery efficiency of the test vehicle in the braking process can be as follows: comparing the preset braking energy recovery efficiency with the braking energy recovery efficiency of the test vehicle in the braking process, when the difference between the preset braking energy recovery efficiency and the braking energy recovery efficiency of the test vehicle in the braking process is smaller than or equal to a numerical threshold, indicating that the performance of the test vehicle is good, and when the difference between the preset braking energy recovery efficiency and the braking energy recovery efficiency of the test vehicle in the braking process is larger than the numerical threshold, indicating that the performance of the test vehicle is poor, and detecting the test vehicle is needed.

For example, the preset braking energy recovery efficiency of the test vehicle is 20% and the numerical threshold is 1%. When the braking energy recovery efficiency of the test vehicle in the braking process is 18%, the difference between the preset braking energy recovery efficiency of the test vehicle and the braking energy recovery efficiency of the test vehicle in the braking process is 2% and is larger than 1%, which indicates that the performance of the test vehicle is poor and the test vehicle needs to be detected. When the braking energy recovery efficiency of the test vehicle in the braking process is 19%, the difference between the preset braking energy recovery efficiency of the test vehicle and the braking energy recovery efficiency of the test vehicle in the braking process is 2% and is equal to 1%, so that the performance of the test vehicle is good, and the test vehicle does not need to be detected.

In addition, according to the braking energy recovery efficiency of the test vehicle in the braking process, the implementation mode for evaluating the performance of the test vehicle can also be as follows: and acquiring braking energy recovery efficiency of the plurality of test vehicles in the braking process, comparing the braking energy recovery efficiency of the plurality of test vehicles in the braking process, and ensuring that the performance of the test vehicle corresponding to the largest braking energy recovery efficiency in the plurality of braking energy recovery efficiency values is the best.

It should be noted that, when the braking energy recovery efficiency of the plurality of test vehicles in the braking process is obtained, the plurality of test vehicles can all travel and brake under the same preset working condition. For example, 3 test vehicles are obtained under the same preset working conditionRunning and braking are carried out, and the same preset working conditions can be as follows: the SOC of the power battery is 60 percent, and the acceleration is-0.8 m/s ² . The 3 test vehicles are test vehicle A, test vehicle B and test vehicle C respectively, the braking energy recovery efficiency of test vehicle A is 35%, the braking energy recovery efficiency of test vehicle B is 40%, and the braking energy recovery efficiency of test vehicle C is 30%. After comparison, the braking energy recovery efficiency of test vehicle B was the greatest, indicating that test vehicle B performed best among the 3 test vehicles.

In the embodiment of the invention, the braking state information of the test vehicle is obtained, and the braking state information can comprise the speed of the test vehicle in the braking process, the rotation speed of the wheels, the voltage of a motor controller in the test vehicle, the current of the motor controller, the moment of inertia of the wheels of the test vehicle, the mass of the test vehicle, the acceleration of the test vehicle and the braking time of the test vehicle. And determining the braking energy recovery efficiency of the test vehicle in the braking process according to the braking state information of the test vehicle. That is, in embodiments of the present invention, By acquiring the voltage and current of the motor controller during braking of the test vehicle,the accuracy of the braking energy recovery efficiency of the test vehicle in the braking process can be more accurately determined by determining the energy recovery efficiency according to the voltage and the current of the motor controller and combining other data, and the accuracy of the evaluation result is improved finally when the vehicle is evaluated according to the braking energy recovery efficiency.

Fig. 5 is a schematic diagram of an apparatus for determining an efficiency of recovering braking energy of an automobile according to an embodiment of the present invention. As shown in fig. 5, the vehicle braking energy recovery efficiency determining apparatus 500 includes:

a first obtaining module 501, configured to obtain first braking state information of a test vehicle, where the braking state information includes a vehicle speed of the test vehicle during braking, a voltage of a motor controller of the test vehicle, a current of the motor controller, a mass of the test vehicle, an acceleration of the test vehicle, and a braking time of the test vehicle;

the determining module 502 is configured to determine a braking energy recovery efficiency of the test vehicle during braking according to the first braking state information of the test vehicle.

Optionally, the first brake state information further includes: the rotational speed of the wheels of the vehicle during braking is tested and the rotational inertia of the wheels of the vehicle is tested.

Optionally, the determining module 502 includes:

the first determining unit is used for determining feedback electric energy generated by the test vehicle in the braking process according to the voltage of the motor controller and the current of the motor controller in the test vehicle, wherein the feedback electric energy refers to electric energy input to a power battery in the vehicle to be tested in the braking process of the vehicle to be tested;

the second determining unit is used for determining braking kinetic energy of the test vehicle in the braking process according to the vehicle speed, the acceleration of the test vehicle, the mass of the test vehicle and the braking time of the test vehicle, wherein the braking kinetic energy refers to energy generated by the test vehicle in the braking process;

the third determining unit is used for determining the rotational kinetic energy of the wheels of the test vehicle in the braking process according to the rotational inertia and the vehicle speed of the wheels of the test vehicle;

a fourth determining unit for determining resistance energy consumed by the test vehicle in a braking process according to the vehicle speed;

Optionally, the first determining unit includes:

And the first determination subunit is used for determining feedback electric energy generated by the test vehicle in the braking process according to the voltage and the screening current of the motor controller in the test vehicle.

A second determination unit including:

the third determination subunit is used for determining braking kinetic energy of the test vehicle in the braking process according to the initial speed of the test vehicle when the braking is started, the final speed of the test vehicle after the braking is finished and the mass of the test vehicle;

a third determination unit including:

the first filtering subunit is used for carrying out first filtering processing on the wheel rotating speed to obtain the filtered wheel rotating speed after the first filtering;

a fourth determining subunit, configured to determine rotational kinetic energy of the wheels of the test vehicle during braking according to rotational inertia of the wheels of the test vehicle and the rotational speed of the filtered wheels;

a fourth determination unit including:

and the fifth determination subunit is used for determining the resistance energy consumed by the resistance of the test vehicle in the braking process according to the filtered vehicle speed and the sliding coefficient.

Optionally, the first determining subunit is further configured to:

E _{returning to} ＝∫UIdt

Wherein E is _{Returning to} The method comprises the steps that feedback electric energy generated by a test vehicle in a braking process is represented, U represents voltage of a motor controller, I represents screening current, and t represents braking time of the test vehicle;

the third determination subunit is further configured to:

wherein E is _{Manufacturing process} Representing braking kinetic energy of the test vehicle during braking, m representing mass of the test vehicle; v1 represents the initial speed of the test vehicle at the start of braking, v2 represents the testEnd speed of the vehicle after braking;

the fourth determination subunit is further configured to:

wherein E is _Rotation The method comprises the steps of representing the rotational kinetic energy of wheels of a test vehicle in the braking process, J represents the rotational inertia, and n represents the rotational speed of a filtered wheel;

the fifth determination subunit is further configured to:

E _{resistance resistor} ＝∫3.6×10 ⁶ ×v×(A+Bv+Cv ² )dt

Wherein E is _{Resistance resistor} Representing resistance energy consumed by resistance of the test vehicle in the braking process, and v represents a filtered vehicle speed; t represents the braking time of the test vehicle, A, B and C represent different sliding coefficients of the test vehicle respectively;

The fifth determining unit is configured to:

or (b)

Optionally, the apparatus 500 for determining an energy recovery efficiency of braking the automobile further includes:

the third acquisition module is used for acquiring state information of the test vehicle under a preset working condition, wherein the preset working condition refers to information, which is required to be predetermined, of the test vehicle before braking;

the evaluation module is used for:

acquiring the preset braking energy recovery efficiency of the test vehicle;

In the embodiment of the invention, the braking state information of the test vehicle is obtained, and the braking state information can comprise the speed of the test vehicle in the braking process, the rotation speed of the wheels, the voltage of a motor controller in the test vehicle, the current of the motor controller, the moment of inertia of the wheels of the test vehicle, the mass of the test vehicle, the acceleration of the test vehicle and the braking time of the test vehicle. And determining the braking energy recovery efficiency of the test vehicle in the braking process according to the braking state information of the test vehicle. That is, in the embodiment of the invention, the accuracy of the braking energy recovery efficiency of the test vehicle in the braking process can be more accurately determined by acquiring the voltage and the current of the motor controller in the braking process of the test vehicle and determining the energy recovery efficiency according to the voltage and the current of the motor controller and combining other data, and further, the accuracy of the evaluation result is improved when the vehicle is evaluated according to the braking energy recovery efficiency.

It should be noted that: the vehicle braking energy recovery efficiency determining device provided in the above embodiment only illustrates the division of the above functional modules when determining the vehicle braking energy recovery efficiency, and in practical application, the above functional allocation may be performed by different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules, so as to complete all or part of the functions described above. In addition, the device for determining the recovery efficiency of braking energy of the automobile provided in the above embodiment and the method embodiment for determining the recovery efficiency of braking energy of the automobile belong to the same concept, and detailed implementation processes of the device are shown in the method embodiment, and are not repeated here.

Fig. 6 is a schematic diagram of an apparatus for determining an efficiency of recovering braking energy of an automobile according to an embodiment of the present invention. The vehicle braking energy recovery efficiency determining apparatus 600 may be: a smart phone, a tablet computer, an MP3 player (Moving Picture Experts Group Audio Layer III, motion picture expert compression standard audio plane 3), an MP4 (Moving Picture Experts Group Audio Layer IV, motion picture expert compression standard audio plane 4) player, a notebook computer, or a desktop computer. The vehicle brake energy recovery efficiency determination device 600 may also be referred to by other names such as user equipment, portable vehicle brake energy recovery efficiency determination device, laptop vehicle brake energy recovery efficiency determination device, and desktop vehicle brake energy recovery efficiency determination device.

In general, the vehicle brake energy recovery efficiency determining apparatus 600 includes: a processor 601 and a memory 602.

Processor 601 may include one or more processing cores, such as a 4-core processor, an 8-core processor, and the like. The processor 601 may be implemented in at least one hardware form of DSP (Digital Signal Processing ), FPGA (Field-Programmable Gate Array, field programmable gate array), PLA (Programmable Logic Array ). The processor 601 may also include a main processor, which is a processor for processing data in an awake state, also called a CPU (Central Processing Unit ), and a coprocessor; a coprocessor is a low-power processor for processing data in a standby state. In some embodiments, the processor 601 may integrate a GPU (Graphics Processing Unit, image processor) for rendering and drawing of content required to be displayed by the display screen. In some embodiments, the processor 601 may also include an AI (Artificial Intelligence ) processor for processing computing operations related to machine learning.

The memory 602 may include one or more computer-readable storage media, which may be non-transitory. The memory 602 may also include high-speed random access memory, as well as non-volatile memory, such as one or more magnetic disk storage devices, flash memory storage devices. In some embodiments, a non-transitory computer readable storage medium in memory 602 is used to store at least one instruction for execution by processor 601 to implement the vehicle braking energy recovery efficiency determination method provided by the method embodiments herein.

In some embodiments, the vehicle braking energy recovery efficiency determining apparatus 600 may further optionally include: a peripheral interface 603, and at least one peripheral. The processor 601, memory 602, and peripheral interface 603 may be connected by a bus or signal line. The individual peripheral devices may be connected to the peripheral device interface 603 via buses, signal lines or a circuit board. Specifically, the peripheral device includes: at least one of radio frequency circuitry 604, a touch display 605, a camera assembly 606, audio circuitry 607, a positioning assembly 608, and a power supply 609.

Peripheral interface 603 may be used to connect at least one Input/Output (I/O) related peripheral to processor 601 and memory 602. In some embodiments, the processor 601, memory 602, and peripheral interface 603 are integrated on the same chip or circuit board; in some other embodiments, either or both of the processor 601, memory 602, and peripheral interface 603 may be implemented on separate chips or circuit boards, which is not limited in this embodiment.

The Radio Frequency circuit 604 is configured to receive and transmit RF (Radio Frequency) signals, also known as electromagnetic signals. The radio frequency circuit 604 communicates with a communication network and other communication devices via electromagnetic signals. The radio frequency circuit 604 converts an electrical signal into an electromagnetic signal for transmission, or converts a received electromagnetic signal into an electrical signal. Optionally, the radio frequency circuit 604 includes: antenna systems, RF transceivers, one or more amplifiers, tuners, oscillators, digital signal processors, codec chipsets, subscriber identity module cards, and so forth. The radio frequency circuit 604 may communicate with other vehicle braking energy recovery efficiency determination devices via at least one wireless communication protocol. The wireless communication protocol includes, but is not limited to: metropolitan area networks, various generations of mobile communication networks (2G, 3G, 4G, and 5G), wireless local area networks, and/or WiFi (Wireless Fidelity ) networks. In some embodiments, the radio frequency circuitry 604 may also include NFC (Near Field Communication, short range wireless communication) related circuitry, which is not limited in this application.

The display screen 605 is used to display a UI (User Interface). The UI may include graphics, text, icons, video, and any combination thereof. When the display 605 is a touch display, the display 605 also has the ability to collect touch signals at or above the surface of the display 605. The touch signal may be input as a control signal to the processor 601 for processing. At this point, the display 605 may also be used to provide virtual buttons and/or virtual keyboards, also referred to as soft buttons and/or soft keyboards. In some embodiments, the display screen 605 may be one, provided with a front panel of the vehicle braking energy recovery efficiency determining apparatus 600; in other embodiments, the display screen 605 may be at least two, respectively disposed on different surfaces of the vehicle braking energy recovery efficiency determining apparatus 600 or in a folded design; in still other embodiments, the display 605 may be a flexible display disposed on a curved surface or a folded surface of the vehicle braking energy recovery efficiency determining apparatus 600. Even more, the display 605 may be arranged in a non-rectangular irregular pattern, i.e., a shaped screen. The display 605 may be made of LCD (Liquid Crystal Display ), OLED (Organic Light-Emitting Diode) or other materials.

The camera assembly 606 is used to capture images or video. Optionally, the camera assembly 606 includes a front camera and a rear camera. In general, a front camera is provided on a front panel of an automobile braking energy recovery efficiency determination device, and a rear camera is provided on a rear surface of the automobile braking energy recovery efficiency determination device. In some embodiments, the at least two rear cameras are any one of a main camera, a depth camera, a wide-angle camera and a tele camera, so as to realize that the main camera and the depth camera are fused to realize a background blurring function, and the main camera and the wide-angle camera are fused to realize a panoramic shooting and Virtual Reality (VR) shooting function or other fusion shooting functions. In some embodiments, camera assembly 606 may also include a flash. The flash lamp can be a single-color temperature flash lamp or a double-color temperature flash lamp. The dual-color temperature flash lamp refers to a combination of a warm light flash lamp and a cold light flash lamp, and can be used for light compensation under different color temperatures.

The audio circuit 607 may include a microphone and a speaker. The microphone is used for collecting sound waves of users and environments, converting the sound waves into electric signals, and inputting the electric signals to the processor 601 for processing, or inputting the electric signals to the radio frequency circuit 604 for voice communication. For the purpose of stereo sound collection or noise reduction, a plurality of microphones may be respectively disposed at different portions of the vehicle braking energy recovery efficiency determining apparatus 600. The microphone may also be an array microphone or an omni-directional pickup microphone. The speaker is used to convert electrical signals from the processor 601 or the radio frequency circuit 604 into sound waves. The speaker may be a conventional thin film speaker or a piezoelectric ceramic speaker. When the speaker is a piezoelectric ceramic speaker, not only the electric signal can be converted into a sound wave audible to humans, but also the electric signal can be converted into a sound wave inaudible to humans for ranging and other purposes. In some embodiments, the audio circuit 607 may also include a headphone jack.

The locating component 608 is used to locate the current geographic location of the vehicle braking energy recovery efficiency determination device 600 to enable navigation or LBS (Location Based Service, location-based services). The positioning component 608 may be a positioning component based on the United states GPS (Global Positioning System ), the Beidou system of China, the Granati system of Russia, or the Galileo system of the European Union.

The power supply 609 is used to power the various components in the vehicle braking energy recovery efficiency determination apparatus 600. The power source 609 may be alternating current, direct current, disposable battery or rechargeable battery. When the power source 609 includes a rechargeable battery, the rechargeable battery may support wired or wireless charging. The rechargeable battery may also be used to support fast charge technology.

In some embodiments, the vehicle braking energy recovery efficiency determination apparatus 600 further includes one or more sensors 610. The one or more sensors 610 include, but are not limited to: acceleration sensor 611, gyroscope sensor 612, pressure sensor 613, fingerprint sensor 614, optical sensor 615, and proximity sensor 616.

The acceleration sensor 611 can detect the magnitudes of accelerations on three coordinate axes of the coordinate system established by the vehicle braking energy recovery efficiency determining apparatus 600. For example, the acceleration sensor 611 may be used to detect components of gravitational acceleration in three coordinate axes. The processor 601 may control the touch display screen 605 to display a user interface in a landscape view or a portrait view according to the gravitational acceleration signal acquired by the acceleration sensor 611. The acceleration sensor 611 may also be used for the acquisition of motion data of a game or a user.

The gyro sensor 612 may detect the body direction and the rotation angle of the vehicle braking energy recovery efficiency determining apparatus 600, and the gyro sensor 612 may collect the 3D motion of the user on the vehicle braking energy recovery efficiency determining apparatus 600 in cooperation with the acceleration sensor 611. The processor 601 may implement the following functions based on the data collected by the gyro sensor 612: motion sensing (e.g., changing UI according to a tilting operation by a user), image stabilization at shooting, game control, and inertial navigation.

The pressure sensor 613 may be disposed at a side frame of the vehicle braking energy recovery efficiency determining apparatus 600 and/or at a lower layer of the touch screen 605. When the pressure sensor 613 is provided at a side frame of the vehicle braking energy recovery efficiency determining apparatus 600, a user's grip signal of the vehicle braking energy recovery efficiency determining apparatus 600 may be detected, and the processor 601 performs a left-right hand recognition or a quick operation according to the grip signal collected by the pressure sensor 613. When the pressure sensor 613 is disposed at the lower layer of the touch display screen 605, the processor 601 controls the operability control on the UI interface according to the pressure operation of the user on the touch display screen 605. The operability controls include at least one of a button control, a scroll bar control, an icon control, and a menu control.

The fingerprint sensor 614 is used for collecting the fingerprint of the user, and the processor 601 identifies the identity of the user according to the fingerprint collected by the fingerprint sensor 614, or the fingerprint sensor 614 identifies the identity of the user according to the collected fingerprint. Upon recognizing that the user's identity is a trusted identity, the processor 601 authorizes the user to perform relevant sensitive operations including unlocking the screen, viewing encrypted information, downloading software, paying for and changing settings, etc. The fingerprint sensor 614 may be provided on the front, rear, or side of the vehicle brake energy recovery efficiency determining apparatus 600. When a physical key or a manufacturer Logo is provided on the vehicle braking energy recovery efficiency determining device 600, the fingerprint sensor 614 may be integrated with the physical key or the manufacturer Logo.

The optical sensor 615 is used to collect ambient light intensity. In one embodiment, processor 601 may control the display brightness of touch display 605 based on the intensity of ambient light collected by optical sensor 615. Specifically, when the intensity of the ambient light is high, the display brightness of the touch display screen 605 is turned up; when the ambient light intensity is low, the display brightness of the touch display screen 605 is turned down. In another embodiment, the processor 601 may also dynamically adjust the shooting parameters of the camera assembly 606 based on the ambient light intensity collected by the optical sensor 615.

The proximity sensor 616, also referred to as a distance sensor, is typically provided on the front panel of the vehicle braking energy recovery efficiency determining apparatus 600. The proximity sensor 616 is used to collect the distance between the user and the front face of the vehicle braking energy recovery efficiency determining apparatus 600. In one embodiment, when the proximity sensor 616 detects that the distance between the user and the front face of the vehicle brake energy recovery efficiency determining apparatus 600 gradually decreases, the processor 601 controls the touch display screen 605 to switch from the bright screen state to the off screen state; when the proximity sensor 616 detects that the distance between the user and the front face of the vehicle brake energy recovery efficiency determining apparatus 600 gradually increases, the processor 601 controls the touch display screen 605 to switch from the off-screen state to the on-screen state.

It will be appreciated by those skilled in the art that the configuration shown in fig. 6 does not constitute a limitation of the vehicle brake energy recovery efficiency determination apparatus 600, and may include more or fewer components than shown, or may combine certain components, or may employ a different arrangement of components.

The embodiment of the application also provides a non-transitory computer readable storage medium, which when the instructions in the storage medium are executed by the processor of the vehicle braking energy recovery efficiency determining device, enables the vehicle braking energy recovery efficiency determining device to execute the vehicle braking energy recovery efficiency determining method provided by the embodiment shown in fig. 1.

The embodiment of the application also provides a computer program product containing instructions, which when run on a computer, cause the computer to execute the method for determining the braking energy recovery efficiency of the automobile provided by the embodiment shown in fig. 1.

Fig. 7 is a schematic diagram of an automobile braking energy recovery efficiency determining system according to an embodiment of the present invention. As shown in fig. 7, the system includes an upper computer 1, a data collector 2, and a test vehicle 3.

The data collector 2 is used for collecting first braking state information of the test vehicle 3, the upper computer 1 is electrically connected with the data collector 2, and the upper computer 1 is used for determining braking energy recovery efficiency of the test vehicle 3 in a braking process according to the first braking state information collected by the data collector 2.

The data collector 2 may be a general data collecting device, such as Vbox, RT3000, canoe, etc., or may be another special data collecting device. The upper computer 1 can be a mobile phone, a notebook computer, a desktop computer and the like.

In addition, as shown in fig. 7, a vehicle diagnosis interface 4 is provided on the test vehicle 3, and the data collector 2 may be connected to the vehicle diagnosis interface 4 to collect first brake state information of the test vehicle 3 during braking. And the data collector 2 is also connected with the upper computer 1, and sends the collected first braking state information to the upper computer 1, and the upper computer 1 determines the braking energy recovery efficiency of the test vehicle 3 in the braking process according to the first braking state information.

It should be noted that, in the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described as different from other embodiments, and identical and similar parts between the embodiments are all enough to be referred to each other.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiment and all such alterations and modifications as fall within the scope of the embodiments of the invention.

Finally, it is further noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or automobile brake energy recovery efficiency determination device that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or automobile brake energy recovery efficiency determination device. Without further limitation, the element defined by the phrase "comprising one … …" does not exclude that there are also other identical elements in a process, method, article or automobile brake energy recovery efficiency determining apparatus that comprises the element.

The foregoing has outlined rather broadly the more detailed description of the invention in order that the detailed description of the invention that follows may be better understood, and in order that the present principles and embodiments may be better understood; meanwhile, as those skilled in the art will vary in the specific embodiments and application scope according to the idea of the present invention, the present disclosure should not be construed as limiting the present invention in summary.

Claims

1. The method for determining the automobile braking energy recovery efficiency is characterized by comprising the following steps of:

determining the braking energy recovery efficiency of the test vehicle in the braking process according to the first braking state information of the test vehicle;

wherein the first braking state information further includes: the wheel rotating speed of the test vehicle in the braking process and the rotational inertia of the wheels of the test vehicle;

The determining, according to the first braking state information of the test vehicle, the braking energy recovery efficiency of the test vehicle in the braking process includes:

determining the braking energy recovery efficiency of the test vehicle in the braking process according to the feedback electric energy, the braking kinetic energy, the rotational kinetic energy and the resistance energy;

determining the rotational kinetic energy of the wheels of the test vehicle in the braking process according to the rotational inertia and the rotational speed of the filter wheels;

before the first braking state information of the test vehicle is acquired, the method for determining the braking energy recovery efficiency of the automobile further comprises the following steps:

taking the state information of the test vehicle under a preset working condition as first braking state information of the test vehicle;

the preset working condition comprises that the speed of the test vehicle is between 30km/h and 10km/h, and the acceleration of the test vehicle is-0.8 m/s ² The speed of the test vehicle is between 80km/h and 10km/h, and the acceleration of the test vehicle is-1.2 m/s ² The speed of the test vehicle is between 120km/h and 10km/h, and the acceleration of the test vehicle is-0.7 m/s ² Is a working condition of the engine.

2. The method for determining the braking energy recovery efficiency of the automobile according to claim 1, wherein the determining the feedback electric energy generated by the test vehicle during braking based on the voltage of the motor controller in the test vehicle and the current of the motor controller comprises:

determining feedback electric energy generated by the test vehicle in the braking process according to the voltage of the motor controller and the screening current;

acquiring a sliding coefficient of the test vehicle in a braking process;

and determining the resistance energy consumed by the resistance of the test vehicle in the braking process according to the filter vehicle speed and the sliding coefficient.

3. The method for determining the braking energy recovery efficiency of the automobile according to claim 2, wherein the determining the feedback electric energy generated by the test vehicle during braking according to the voltage of the motor controller and the screening current comprises:

E _{returning to} ＝∫UIdt

Wherein E is _{Returning to} Representing feedback electric energy generated by the test vehicle in the braking process, wherein U represents the voltage of the motor controller, and I represents the screening currentT represents the braking time of the test vehicle;

E _{resistance resistor} ＝∫3.6×10 ⁶ ×v×(A+Bv+Cv ² )dt

or (b)

4. The method for determining the braking energy recovery efficiency of the automobile according to claim 1, characterized in that after determining the braking energy recovery efficiency of the test vehicle during braking, the method for determining the braking energy recovery efficiency of the automobile further comprises:

acquiring the preset braking energy recovery efficiency of the test vehicle;

5. An automobile brake energy recovery efficiency determining apparatus, characterized by comprising:

a processor;

a memory for storing processor-executable instructions;

wherein the processor is configured to perform the steps of the method of any one of claims 1 to 4.

6. A computer readable storage medium having stored thereon instructions which, when executed by a processor, implement the steps of the method of any one of claims 1 to 4.

7. The automobile braking energy recovery efficiency determining system is characterized by comprising an upper computer, a data acquisition device and a test vehicle;

The upper computer is used for determining the braking energy recovery efficiency of the test vehicle in the braking process according to the first braking state information acquired by the data acquisition device;

the first braking state information comprises a vehicle speed of the test vehicle in a braking process, a voltage of a motor controller of the test vehicle, a current of the motor controller, a mass of the test vehicle, an acceleration of the test vehicle and a braking time of the test vehicle;

the first braking state information further includes: the wheel rotating speed of the test vehicle in the braking process and the rotational inertia of the wheels of the test vehicle;

the upper computer is also used for: determining feedback electric energy generated by the test vehicle in the braking process according to the voltage of the motor controller in the test vehicle and the current of the motor controller;

Before the data collector acquires the first braking state information of the test vehicle, the upper computer is further used for: