DE102015112711A1 - Method and system for controlling speeding violations of an electric vehicle - Google Patents

Abstract

A method and system for controlling speeding violations of an electric vehicle are proposed. First, an actual vehicle speed is compared with a target vehicle maximum speed to calculate a first torque limit coefficient; thereafter, a current revolution speed of an engine is compared with a target maximum revolution speed of the engine to calculate a second torque limit coefficient; thereafter, the lesser of the first torque limit coefficient and the second torque limit coefficient is selected to obtain a torque limit coefficient; and finally, a maximum torque of the engine is multiplied by the torque limit coefficient to obtain an output torque limit of the engine. By using the vehicle speed and the rotational speed of the engine for double protection, both the control accuracy and the driving safety are improved. Moreover, in the prior art, only the rotational speed of the engine is used, resulting in the problem that the output torque is subject to fluctuation while the vehicle exceeds the vehicle speed, and this problem is effectively avoided. By using the vehicle speed and the rotational speed of the engine for dual monitoring, performance of the power is ensured and the driving safety of the vehicle is improved.

Description

TECHNICAL AREA

The present disclosure relates to the field of electric vehicles and, more particularly, to a method and system for controlling speeding violations of an electric vehicle.

BACKGROUND

Electric vehicles have the advantage that they are emission-free, do not pollute, have high energy conversion efficiency, and are quiet, making them an important solution to the urban vehicle problem. The development of the electric vehicle will have a decisive impact on the transformation of the industrial structure, the improvements of innovation capability and the market competitiveness of key fields, as well as the coordinated development of the economic society. The value of the EV not only relates to energy storage and emission reduction, but also to the revolution in energy consumption and the resulting optimization of the energy structure. The electric vehicle that can solve the issues of oil dependency, pollution, fuel gas emissions and energy security is the last resort for developing alternative drive vehicles.

For the safety of the vehicle and the driver, the maximum speed of a vehicle must be limited during high-speed driving and, at the same time, the vehicle speed increases with the increase of the engine rotational speed during the running of the vehicle. If the engine's rotational speed reaches a certain high value, it should be limited for reasons of engine life and driving safety. In conventional vehicles, the vehicle speed is limited not only to the output power and the torque of the engine, but also to the transmission ratio of the transmission. However, the maximum speed of electric vehicles is limited to the drive motor and the manual transmission, so that the vehicle head unit and the engine controller are required to respectively limit the vehicle speed and the rotational speed of the engine.

The solution for limiting the speed of electric vehicles in the prior art is in 1 shown. The rotational speed signal of the engine is detected by the vehicle controller, and the torque coefficient of the engine is obtained by a look-up table of the current rotational speed of the engine. The maximum torque of the motor is multiplied by the coefficient to obtain the torque limit of the motor. For this solution, the table looks like this: rotation speed 6000 9000 9150 9300 9500 coefficient 1 1 0.5 0 0

It can be seen that the revolution speed limit coefficient is always selected to be 1 before the revolution speed reaches 9000 rpm (calibration value), and that the revolution speed limit coefficient becomes 0 when the revolution speed is 9300 rpm reached. The difference algorithm is used to calculate when the rotational speed is between 9000 rpm and 9300 rpm. Finally, the revolution speed limit coefficient is multiplied by the maximum analysis torque of the engine to obtain the torque limit coefficient of the engine.

In the above solution, the revolution speed limit coefficient is obtained by looking up the one-dimensional table after the revolution speed signal of the motor. The revolution speed limit coefficient will be 0 after the revolution speed reaches 9300 rpm (calibration value), so that this revolution speed limit coefficient is multiplied by the maximum available engine torque and the obtained engine torque is 0. When driving at high speed when the engine torque becomes 0, the vehicle loses drive power and the vehicle speed will decrease under the influence of friction. When the accelerator pedal is pressed when driving at high speed is, the engine torque is subject to fluctuations, so that the vehicle speed alternately increases and decreases, which will lead to the erroneous assumption that the driver is a fault, causing panic and driving safety is impaired.

SUMMARY

The object of the embodiments of the present disclosure is to solve at least some of the problems existing in the prior art at least to some extent.

According to embodiments of one aspect of the present disclosure, a method for controlling speeding violations of an electric vehicle is proposed. The method comprises the steps of: comparing a current vehicle speed with a desired vehicle maximum speed to calculate a first torque limit coefficient; Comparing a current rotational speed of an engine with a target maximum rotational speed of the engine to calculate a second torque limit coefficient; Selecting the lower value of the first torque limit coefficient and the second torque limit coefficient to obtain a torque limit coefficient; Multiplying a maximum torque of the engine by the torque limit coefficient to obtain an output torque limit of the engine.

With the aid of the method of controlling speeding of the electric vehicle according to embodiments of the present disclosure, both the control accuracy and the driving safety are improved by using the vehicle speed and the rotational speed of the engine for double protection. Moreover, in the prior art, only the rotational speed of the engine is used, resulting in the problem that the output torque is subject to fluctuation while the vehicle exceeds the vehicle speed, and this problem is effectively avoided. By using the vehicle speed and the rotational speed of the engine for dual monitoring, performance of the power is ensured and the driving safety of the vehicle is improved.

Preferably, comparing a current vehicle speed with a desired maximum vehicle speed to calculate a first torque limit coefficient comprises: selecting the first torque limit coefficient as 1 if the current vehicle speed is less than the desired maximum vehicle speed; Calculating a difference between the current vehicle speed and the target maximum vehicle speed, performing PID regulation, and outputting the first torque limit coefficient if the current vehicle speed is greater than the target vehicle maximum speed. With the aid of PID regulation, the current vehicle speed can stably approach the target vehicle maximum speed, so as to avoid an influence of an excessive increase.

Preferably, the method further comprises the following while calculating the first torque limit coefficient: performing upper and lower limit processing after the PID control, and thereafter outputting the first torque limit coefficient. Since a large fluctuation can be caused by a PID control failure, the output should be limited by performing the upper and lower limit processing within a reasonable range, thus ensuring reliability of the control.

Preferably, comparing a current rotational speed of an engine with a target maximum rotational speed of the engine to calculate a second torque limit coefficient comprises: selecting the second torque limit coefficient as 1 if the current rotational speed of the engine is less than the target maximum rotational velocity of the motor; Calculating a difference between the current rotational speed of the engine and the target maximum rotational speed of the engine, performing a PID control, and outputting the second torque limit coefficient if the current rotational speed of the engine is greater than the target maximum rotational speed of the engine. With the help of PID regulation, the current engine revolution speed can more closely approach the engine target maximum engine revolution speed.

Preferably, the method further comprises the following while calculating the second torque limit coefficient: performing upper and lower limit processing after the PID control, and then outputting the second torque limit coefficient. Because a big fluctuation can be caused by a PID control failure, the output should be adjusted by performing the upper and lower limit processing within a reasonable range, thus ensuring reliability of the control.

According to embodiments of another aspect of the present disclosure, a system for controlling speeding of an electric vehicle is proposed. The system comprises: a first calculation module configured to compare a current vehicle speed with a desired maximum vehicle speed to calculate a first torque limit coefficient; a second calculation module configured to compare a current revolution speed of an engine with a target maximum revolution speed of the engine so as to calculate a second torque limit coefficient; a minimum value selection module configured to select the lower value of the first torque limit coefficient and the second torque limit coefficient so as to obtain a torque limit coefficient; a search engine configured to multiply a maximum torque of the engine by the torque limit coefficient so as to obtain an output torque limit of the engine.

With the aid of the electric vehicle speed override control system according to embodiments of the present disclosure, both the control accuracy and the driving safety are improved by using the vehicle speed and the engine speed for double protection. Moreover, in the prior art, only the rotational speed of the engine is used, resulting in the problem that the output torque is subject to fluctuation while the vehicle exceeds the vehicle speed, and this problem is effectively avoided. By using the vehicle speed and the rotational speed of the engine for dual monitoring, performance of the power is ensured and the driving safety of the vehicle is improved.

Preferably, the first calculation module comprises: a first comparison unit configured to compare the current vehicle speed with the target vehicle maximum speed; a first vehicle speed calculation unit configured to select the first torque limit coefficient as 1 when the current vehicle speed is less than the target vehicle maximum speed; a second vehicle speed calculating unit configured to calculate a difference between the current vehicle speed and the target maximum vehicle speed, to perform PID control, and to output the first torque limit coefficient when the current vehicle speed is greater than the target vehicle maximum speed. With the aid of PID regulation, the current vehicle speed can stably approach the target vehicle maximum speed, so as to avoid an influence of an excessive increase.

Preferably, the second vehicle speed calculation unit is further configured to perform upper and lower limit processing after the PID control and thereafter to output the first torque limit coefficient. Since a large fluctuation can be caused by a PID control failure, the output should be controlled by performing the upper and lower limit processing within a reasonable range, thus ensuring reliability of the control.

Preferably, the second calculation module comprises: a second comparison unit configured to compare the current rotational speed of the engine with the target maximum rotational speed of the engine; a first revolution speed calculation unit configured to select the second torque limit coefficient as 1 when the current revolution speed of the engine is less than the target maximum revolution speed of the engine; a second revolution speed calculating unit configured to calculate a difference between the current revolution speed of the engine and the target maximum revolution speed of the engine, to perform PID regulation, and to output the second torque limit coefficient when the current revolution speed of the engine is greater than the target maximum rotation speed of the motor. With the help of PID regulation, the current engine revolution speed can more closely approach the engine target maximum engine revolution speed.

Preferably, the second revolution speed calculating unit is further configured to perform upper and lower limit processing after the PID regulation and thereafter to output the second torque limit coefficient. Since a large fluctuation can be caused by a PID control failure, the output should be controlled by performing the upper and lower limit processing within a reasonable range, thus ensuring reliability of the control.

According to embodiments of another aspect of the present disclosure, a readable storage medium for storing a program code is proposed. While executing the program code, the method of controlling speeding of the electric vehicle is executed as described above.

BRIEF DESCRIPTION OF THE DRAWING

In order to better understand the present disclosure, the further detailed descriptions are made with reference to embodiments of the present disclosure and together with the drawings. Show it:

1 a schematic diagram of a method for controlling speed overruns from the prior art;

2 10 is a flowchart of a method for controlling speeding violations of an electric vehicle according to an embodiment of the present disclosure;

3 a schematic diagram of a vehicle control device according to an embodiment of the present disclosure;

4 a flowchart of a method for controlling speeding of an electric vehicle by the vehicle head unit according to an embodiment of the present disclosure;

5 a schematic diagram of the method for controlling speeding of an electric vehicle by the vehicle head unit according to an embodiment of the present disclosure;

6 12 is a block diagram of a system for controlling speeding of an electric vehicle according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

In the following, embodiments of the present disclosure will be discussed in detail. Examples of the embodiments are shown in a drawing. The same or similar elements and the elements having the same or similar functions throughout the descriptions have identical reference numerals. The embodiments described herein with reference to the drawings are illustrative and are used to fundamentally understand the present disclosure. The embodiments are not to be interpreted as limiting the present disclosure.

A method for controlling speeding of an electric vehicle according to embodiments of the present disclosure is mainly used in a vehicle head apparatus of the electric vehicle for limiting an output torque of an engine. The method is implemented by a program code which can execute the following program.

Embodiment 1

• 1. Zuerst wird eine aktuelle Fahrzeuggeschwindigkeit mit einer Soll-Fahrzeughöchstgeschwindigkeit verglichen, um einen ersten Drehmomentsgrenzen-Koeffizienten zu berechnen. Dieser Vorgang umfasst die folgenden Schritte.

This embodiment proposes a method for controlling speeding of an electric vehicle. As in 2 As shown, the method includes the following steps.

• 1. First, an actual vehicle speed is compared with a target vehicle maximum speed to calculate a first torque limit coefficient. This process includes the following steps.

The first torque limit coefficient is selected as 1 if the current vehicle speed is less than the target vehicle maximum speed. The target vehicle maximum speed is a maximum speed for the vehicle. Since the vehicle speed does not exceed the target maximum vehicle speed, it is not necessary to restrict a torque so that the first torque limit coefficient is selected as 1 based on this vehicle speed.

A difference between the current vehicle speed and the target vehicle maximum speed is calculated, PID regulation is performed, and the first torque limit coefficient is output when the current vehicle speed is greater than the target vehicle maximum speed. In a preferred embodiment, to avoid a sudden change caused by a PID mismatch, it is necessary to perform upper and lower limit processing after PID regulation so as to limit the output within a reasonable range. With the aid of PID regulation, the current vehicle speed can stably approach the target vehicle maximum speed, so as to avoid an influence of an excessive increase.

PID regulation refers to regulation via PID control. The PID control, which includes a dosing unit, an integration unit and a differentiation unit, performs the control by dosing, integrating and differentiating. A relationship between an input e (t) and an output u (t) of the PID controller is as follows: u (t) = kp [e (t) + 1 / TIe (t) dt + TD * de (t) / dt] wherein an upper limit and a lower limit of integration in the formula are 0 and t, respectively.

• 2. Danach wird eine aktuelle Umdrehungsgeschwindigkeit eines Motors mit einer Soll-Höchstumdrehungsgeschwindigkeit des Motors verglichen, um einen zweiten Drehmomentsgrenzen-Koeffizienten zu berechnen. Dieser Vorgang umfasst die folgenden Schritte.

As a result, a transfer function thereof is G (s) = U (s) / E (s) = kp [1 + 1 / (TI * s) + TD * s] where kp is a proportional coefficient, TI is an integration time constant, and TD is a differentiation time constant.

• 2. Thereafter, a current rotational speed of an engine is compared with a target maximum rotational speed of the engine to calculate a second torque limit coefficient. This process includes the following steps.

The second torque limit coefficient is selected to be 1 if the current rotational speed of the motor is less than the target maximum rotational speed of the motor. Since the rotational speed of the engine does not exceed the target maximum rotational speed of the engine, it is not necessary to adjust the rotational speed of the engine so that the second torque limit coefficient is selected as 1.

• 3. Danach wird der geringere Wert des ersten Drehmomentsgrenzen-Koeffizienten und des zweiten Drehmomentsgrenzen-Koeffizienten ausgewählt, um einen Drehmomentsgrenzen-Koeffizienten zu erhalten. Da ein gewisses funktionelles Verhältnis zwischen der Umdrehungsgeschwindigkeit des Motors und der Fahrzeuggeschwindigkeit besteht, wird durch das Auswählen eines geringeren Wertes ein doppelter Schutz für das Fahrzeug ausgeübt und somit die Kontrollgenauigkeit verbessert.
• 4. Schließlich wird ein maximales Drehmoment des Motors mit dem Drehmomentsgrenzen-Koeffizienten multipliziert, um einen Ausgabedrehmomentsgrenzwert des Motors zu erhalten.

A difference between the current revolution speed of the engine and the target maximum revolution speed of the engine is calculated, PID regulation is performed, and the second torque limit coefficient is output when the current revolution speed of the engine is greater than the target maximum revolution speed of the engine. Similar to adjusting the vehicle speed, in a preferred embodiment, upper and lower limit processing is performed after the PID control so as to limit the output after PID regulation within a reasonable range. With the aid of PID regulation, the current engine revolution speed can stably approach the target vehicle maximum speed so as to avoid an influence of excessive increase.

• 3. Thereafter, the lesser of the first torque limit coefficient and the second torque limit coefficient is selected to obtain a torque limit coefficient. Since there is some functional relationship between the rotational speed of the engine and the vehicle speed, selecting a lower value will provide double protection for the vehicle and thus improve control accuracy.
• 4. Finally, a maximum torque of the engine is multiplied by the torque limit coefficient to obtain an output torque limit of the engine.

The method for controlling speeding of the electric vehicle is proposed according to embodiments of the present disclosure. First, a current vehicle speed is compared with a target vehicle maximum speed to a first To calculate torque limit coefficients; thereafter, a current revolution speed of an engine is compared with a target maximum revolution speed of the engine to calculate a second torque limit coefficient; thereafter, the lesser of the first torque limit coefficient and the second torque limit coefficient is selected to obtain a torque limit coefficient; and finally, a maximum torque of the engine is multiplied by the torque limit coefficient to obtain an output torque limit of the engine. By using the vehicle speed and the rotational speed of the engine for double protection, both the control accuracy and the driving safety are improved. Moreover, in the prior art, only the rotational speed of the engine is used, resulting in the problem that the output torque is subject to fluctuation while the vehicle exceeds the vehicle speed, and this problem is effectively avoided. By using the vehicle speed and the rotational speed of the engine for dual monitoring, performance of the power is ensured, and the driving safety of the vehicle is improved.

Embodiment 2

A method for controlling speeding of an electric vehicle is proposed. The method relates to two controllers comprising a vehicle control unit configured to control an overall condition of the vehicle and a motor controller configured to control the operation of the engine.

As in 3 1, the vehicle-mounted vehicle includes: an input module configured to receive signals from other controllers and peripherals, such as a shift signal, an accelerator pedal signal, an engine revolution speed signal, a speed-restriction coefficient module configured to calculate a speed-restriction coefficient ; and an output module configured to communicate a required torque signal to the engine controller.

The input module is designed primarily to receive the signals sent by other controllers and peripherals to the vehicle controller. A switching device sends a current switching state of the vehicle hardwired to the vehicle control unit. The shifting device has three states: D (forward), N (neutral) and R (reverse). The solution in this embodiment relates to the forward gear. The accelerator sends a current driving project of the driver hardwired to the vehicle control unit.

Since the electric vehicle of this embodiment is applicable to indirect driving, there are a variety of functional relationships between the rotational speed of the engine and the vehicle speed. As a result, in this embodiment, both the revolution speed of the engine and the vehicle speed are detected. This improves not only the control accuracy but also the driving safety.

The engine controller is configured to receive and execute the vehicle speed limit transmitted from the vehicle controller, and a revolution speed limiting module disposed in the engine controller is configured to restrict the maximum revolution speed of the engine so as to perform a reverse protection function.

The speed-limiting coefficient module is designed primarily for calculating a speed-limiting coefficient while the vehicle is running. The coefficient is multiplied by an analysis torque of the engine to obtain a motor torque. The speed restriction coefficient is obtained by the following steps, of which a flowchart in FIG 4 is shown and a schematic diagram of the process in 5 is shown.

First, a current vehicle speed is compared with a desired vehicle maximum speed. If the current vehicle speed is less than the target vehicle maximum speed, a limit coefficient 1 is output without restricting the current vehicle speed. Otherwise, a difference between the current vehicle speed and the target vehicle maximum speed is calculated, PID regulation is performed, upper and lower limit processing is performed, and a first torque limit coefficient is output.

Thereafter, a current revolution speed of an engine is compared with a target maximum revolution speed of the engine. If the current revolution speed of the engine is less than the target maximum revolution speed of the engine, a limit coefficient 1 is output without restricting the current revolution speed of the engine. Otherwise, a difference between the current revolution speed of the engine and the target maximum revolution speed of the engine is calculated, PID regulation is performed, upper and lower limit processing is performed, and a second torque limit coefficient is output.

Thereafter, the lower value of the first torque limit coefficient and the second torque limit coefficient are selected, and a maximum torque of the motor is multiplied by the smaller value to obtain an output torque limit value of the motor. Thereby, it can be ensured that, when the current rotational speed of the engine is greater than the target maximum rotational speed of the engine or the current vehicle speed is greater than the target maximum vehicle speed, the vehicle is traveling at the target maximum rotational speed of the engine or the target vehicle maximum speed, and thus a double protection is implemented, fluctuations of the driving force are prevented and the ride comfort of the vehicle is ensured.

Finally, in this embodiment, the engine controller receives the engine torque transmitted by the vehicle controller and controls the engine to execute that engine torque.

In this embodiment, the vehicle management device receives the vehicle speed signal and the engine revolution speed signal, determines whether each of the two signals reaches a threshold, performs PID regulation and boundary processing on the threshold-surpassing signal, and thereafter selects a lower limit coefficient by comparison out. The engine controller receives a restriction signal and calculates an output revolution speed of the engine. As a result, the ride comfort is improved, the engine is protected and the vehicle speed is controlled and thus the driving safety is improved. In this embodiment, both the vehicle speed and the rotational speed of the motor are used for limiting, and the safety is promoted by this double protection.

Embodiment 3

This embodiment proposes a system for controlling speeding of an electric vehicle. As in 6 10, the system includes: a first calculation module configured to compare a current vehicle speed with a desired maximum vehicle speed so as to calculate a first torque limit coefficient; a second calculation module configured to compare a current revolution speed of an engine with a target maximum revolution speed of the engine so as to calculate a second torque limit coefficient; a minimum value selection module configured to select the lower value of the first torque limit coefficient and the second torque limit coefficient so as to obtain a torque limit coefficient; a search engine configured to multiply a maximum torque of the engine by the torque limit coefficient so as to obtain an output torque limit of the engine.

In this embodiment, the first calculation module comprises: a first comparison unit configured to compare the current vehicle speed with the target vehicle maximum speed; a first vehicle speed calculation unit configured to select the first torque limit coefficient as 1 when the current vehicle speed is less than the target vehicle maximum speed; a second vehicle speed calculating unit configured to calculate a difference between the current vehicle speed and the target maximum vehicle speed, to perform PID control, and to output the first torque limit coefficient when the current vehicle speed is greater than the target vehicle maximum speed.

In another preferred embodiment, the second vehicle speed calculation unit is further configured to perform upper and lower limit processing after the PID control and thereafter to output the first torque limit coefficient.

In the embodiment, the second calculation module comprises: a second comparison unit, which is used to compare the current rotational speed of the engine with the target speed Maximum rotational speed of the engine is designed; a first revolution speed calculation unit configured to select the second torque limit coefficient as 1 when the current revolution speed of the engine is less than the target maximum revolution speed of the engine; a second revolution speed calculating unit configured to calculate a difference between the current revolution speed of the engine and the target maximum revolution speed of the engine, to perform PID regulation, and to output the second torque limit coefficient when the current revolution speed of the engine is greater than the target maximum rotation speed of the motor.

In a preferred embodiment, the second revolution speed calculation unit is further configured to perform upper and lower limit processing after the PID regulation and thereafter to output the second torque limit coefficient.

With the aid of the electric vehicle speed override control system according to embodiments of the present disclosure, both the control accuracy and the driving safety are improved by using the vehicle speed and the engine speed for double protection. Moreover, in the prior art, only the rotational speed of the engine is used, resulting in the problem that the output torque is subject to fluctuation while the vehicle exceeds the vehicle speed, and this problem is effectively avoided. By using the vehicle speed and the rotational speed of the engine for dual monitoring, performance of the power is ensured and the driving safety of the vehicle is improved.

Embodiments of the present disclosure further provide a readable storage medium for storing a program code. While executing the program code, the method of controlling speeding of the electric vehicle is executed as described above.

Reference throughout this specification to "one embodiment," "some embodiments," "a particular embodiment," "another example," "an example," "a specific example," or "some examples" means that a particular feature , a particular structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or at least one example of the present disclosure. Thus, the occurrences of the above formulations throughout the specification do not necessarily refer to the same embodiment or example of the present disclosure. Furthermore, the particular features, structures, materials or properties may be combined in any suitable manner in one or more embodiments or in one or more examples. In addition, various embodiments or examples and the features of various embodiments or examples may be combined by non-contradictory practitioners.

In addition, terms such as "first" and "second" are used herein for descriptive purposes and are not intended to indicate or imply relative importance or meaning, or to imply the number of specified technical features. Thus, the feature defined by "first" and "second" may comprise this feature once or several times. In the description of the present invention, "a plurality of" means at least two, such as two or three, unless otherwise specified.

Each process or method described in the flowchart or otherwise may be understood as a module, segment, or section that includes one or more executable instruction codes of the method steps configured to perform a particular logical function or operation. and the preferred embodiments of the present disclosure include further steps wherein the steps may be accomplished in sequences other than those shown or in question, such as in near concurrent or reverse order, which will be apparent to those skilled in the art to which embodiments of the can be understood.

The logic and / or method steps set forth herein or otherwise described in the flowchart, such as a constant sequence table of the executable code to perform a logical function, may be implemented on any computer-readable storage medium so as to be understood by the code execution system. the device or resources (such as a computer-based system, system comprising a processor, or other systems that obtain codes from the code execution system, device, and resources and execute the codes) to be used or with the code execution system to be used to be combined with the device or resources. With regard to the description of the present invention, the "computer-readable storage medium" may include any device that incorporates, deposits, communicates, distributes, or communicates a program so as to be used by or with the code execution system, apparatus, or resources Code execution system, device or resources to be combined. The computer readable medium includes specific examples (non-exhaustive list): a connection portion (an electronic device) with one or more cable assemblies, a portable computer disk cartridge (a magnetic device), a random access memory (RAM), a read only memory (ROM) ), an electrically programmable read-only memory (EPROM or flash memory), a fiber optic device or a CD-ROM. In addition, the computer-readable storage medium may even be paper or other program-written convenient medium, as the paper or serviceable medium may be optically scanned and then edited, decoded, or otherwise handled in a different manner to the program stored in the computer memory can be deposited to receive electronically.

It should be understood that any part of the present disclosure may be implemented by the hardware, software, firmware, or combinations thereof. In the above embodiments of the present invention, the plurality of process steps or methods may be implemented by the software or hardware stored in the computer memory and executed by the useful code execution system. For example, when the plurality of method steps or methods are to be implemented by the hardware, as in another embodiment of the present invention, one of the following known technologies or a combination thereof may be used, such as a discrete logic circuit with logic gates for the implementation of various logical functions when using one or more data signals, an application specific integrated circuit with suitable logic gates, a Programmable Gate Array (PGA) or a Field Programmable Gate Array (FPGA).

It will be understood by those skilled in the art that the steps in the method of the above embodiments may be implemented in their entirety or partially by commands to appropriate hardware via programs, the program may be stored in a computer readable storage medium, and the program may include one step or combinations of steps of the procedure when the program is executed.

In addition, each functional unit in the present disclosure may be integrated in a secondary module, or each functional unit exists as an independent unit, or two or more functional units may be integrated in one module. The integrated module may be embodied as part of hardware or as part of software. If the integrated module is designed as part of software and is sold or used as an independent product, it may be stored in the computer-readable storage medium.

The computer readable storage medium may include RAM, magnetic storage disks, or optical storage disks.

Although embodiments of the present disclosure have been shown and described above, those skilled in the art will understand that the above embodiments are exemplary and not to be construed as limiting the present disclosure and that modifications, alternatives, and modifications to the embodiments may be made by those skilled in the art without departing from Scope of the present disclosure.

Claims (11)

A method of controlling overspeed of an electric vehicle, comprising: comparing a current vehicle speed with a desired vehicle maximum speed to calculate a first torque limit coefficient; Comparing a current rotational speed of an engine with a target maximum rotational speed of the engine to calculate a second torque limit coefficient; Selecting the lower value of the first torque limit coefficient and the second torque limit coefficient to obtain a torque limit coefficient; Multiplying a maximum torque of the engine by the torque limit coefficient to obtain an output torque limit of the engine. The method of claim 1, wherein comparing a current vehicle speed with a desired maximum vehicle speed to calculate a first torque limit coefficient comprises: Selecting the first torque limit coefficient as 1 if the current vehicle speed is less than the desired maximum vehicle speed; Calculating a difference between the current vehicle speed and the target maximum vehicle speed, performing PID regulation, and outputting the first torque limit coefficient if the current vehicle speed is greater than the target vehicle maximum speed. The method of claim 2, further comprising the following during computing the first torque limit coefficient: performing upper and lower bound processing after the PID control and thereafter outputting the first torque limit coefficient. The method of claim 1, wherein comparing a current rotational speed of an engine to a target maximum rotational speed of the engine to calculate a second torque limit coefficient comprises: Selecting the second torque limit coefficient as 1 if the current rotational speed of the motor is less than the target maximum rotational speed of the motor; Calculating a difference between the current rotational speed of the engine and the target maximum rotational speed of the engine, performing a PID control, and outputting the second torque limit coefficient if the current rotational speed of the engine is greater than the target maximum rotational speed of the engine. The method of claim 4, further comprising the following during computing the second torque limit coefficient: performing upper and lower limit processing after the PID control and thereafter outputting the second torque limit coefficient. A system for controlling speeding of an electric vehicle, comprising: a first calculation module configured to compare a current vehicle speed with a target vehicle maximum speed so as to calculate a first torque limit coefficient; a second calculation module configured to compare a current revolution speed of an engine with a target maximum revolution speed of the engine so as to calculate a second torque limit coefficient; a minimum value selection module configured to select the lower value of the first torque limit coefficient and the second torque limit coefficient so as to obtain a torque limit coefficient; a search engine configured to multiply a maximum torque of the engine by the torque limit coefficient so as to obtain an output torque limit of the engine. The system of claim 6, wherein the first calculation module comprises: a first comparison unit configured to compare the current vehicle speed with the target vehicle maximum speed; a first vehicle speed calculation unit configured to select the first torque limit coefficient as 1 when the current vehicle speed is less than the target vehicle maximum speed; a second vehicle speed calculating unit configured to calculate a difference between the current vehicle speed and the target maximum vehicle speed, to perform PID control, and to output the first torque limit coefficient when the current vehicle speed is greater than the target vehicle maximum speed. The system of claim 7, wherein the second vehicle speed calculation unit is further configured to perform upper and lower limit processing after the PID control and thereafter to output the first torque limit coefficient. The system of any of claims 6-8, wherein the second calculation module comprises: a second comparison unit configured to compare the current rotational speed of the engine with the target maximum rotational speed of the engine; a first revolution speed calculation unit configured to select the second torque limit coefficient as 1 when the current revolution speed of the engine is less than the target maximum revolution speed of the engine; a second revolution speed calculating unit configured to calculate a difference between the current revolution speed of the engine and the target maximum revolution speed of the engine, to perform PID regulation, and to output the second torque limit coefficient when the current revolution speed of the engine is greater than the target maximum rotation speed of the motor. The system of claim 9, wherein the second revolution speed calculation unit is further configured to perform upper and lower limit processing after the PID regulation and thereafter to output the second torque limit coefficient. A readable storage medium for storing a program code during execution of the program code for executing the method for controlling speeding of the electric vehicle according to any one of claims 1-5.

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