阅读说明：本技术 电容的放电方法、装置、系统和存储介质 (Capacitor discharging method, device and system and storage medium ) 是由 冯江华 梅文庆 连国一 文宇良 李程 黄佳德 郑汉锋 曾小凡 杨帆 胡亮 胡仙 于 2020-05-21 设计创作，主要内容包括：本发明公开了一种电容的放电方法、装置、系统和存储介质,方法包括：若接收到放电指令,获取永磁电机的转子位置角和永磁电机的输出电流；根据永磁电机的输出电流和给定放电电流幅值,确定永磁电机的矢量控制中的矢量电压的校准电压幅值；通过校准电压幅值和转子位置角,对输出电流对应的输出电压进行调节,得到目标电压；基于目标电压,生成矢量电压,以使永磁电机在矢量电压的控制下,对电容进行放电。采用本发明的技术方案,能够在电流采样出现零飘过大或者反馈不准确的情况下,保证交轴电流为0,直轴电流不为0,提高了永磁电机维持静止状态的鲁棒性,进而提高了放电可靠性。(The invention discloses a method, a device and a system for discharging a capacitor and a storage medium, wherein the method comprises the following steps: if a discharge instruction is received, acquiring a rotor position angle of the permanent magnet motor and an output current of the permanent magnet motor; determining a calibration voltage amplitude of a vector voltage in vector control of the permanent magnet motor according to the output current of the permanent magnet motor and a given discharge current amplitude; adjusting output voltage corresponding to the output current through calibrating the voltage amplitude and the rotor position angle to obtain target voltage; and generating a vector voltage based on the target voltage so that the permanent magnet motor discharges the capacitor under the control of the vector voltage. By adopting the technical scheme of the invention, the quadrature axis current is ensured to be 0 and the direct axis current is not 0 under the condition that zero drift is too large or the feedback is inaccurate in current sampling, so that the robustness of the permanent magnet motor in a static state is improved, and the discharge reliability is further improved.)

1. The method for discharging the capacitor is applied to control equipment of a permanent magnet motor, and comprises the following steps:

if a discharge instruction is received, acquiring a rotor position angle of the permanent magnet motor and an output current of the permanent magnet motor;

determining a calibration voltage amplitude of a vector voltage in vector control of the permanent magnet motor according to the output current of the permanent magnet motor and a given discharge current amplitude;

adjusting the output voltage corresponding to the output current through the calibration voltage amplitude and the rotor position angle to obtain a target voltage;

and generating the vector voltage based on the target voltage so that the permanent magnet motor discharges the capacitor under the control of the vector voltage.

2. The method of claim 1, wherein determining a calibration voltage magnitude of a vector voltage in vector control of the permanent magnet motor based on the output current of the permanent magnet motor and a given discharge current magnitude comprises:

carrying out coordinate transformation on the output current to obtain alpha-axis current and beta-axis current;

calculating the alpha-axis current and the beta-axis current to obtain a feedback current amplitude;

and carrying out proportional integral control on the feedback current amplitude and the given discharge current amplitude to obtain the calibration voltage amplitude.

3. The method of claim 2, wherein the adjusting the output voltage corresponding to the output current by the calibration voltage amplitude and the rotor position angle to obtain a target voltage comprises:

under the constraint of the rotor position angle, carrying out coordinate decomposition on the calibration voltage amplitude to obtain a first calibration voltage and a second calibration voltage;

regulating the quadrature-axis voltage corresponding to the direct-axis current by using the first calibration voltage to obtain a target quadrature-axis voltage larger than 0;

regulating the direct axis voltage corresponding to the quadrature axis current by using the second calibration voltage to obtain a target direct axis voltage equal to 0;

correspondingly, generating the vector voltage based on the target voltage comprises:

and performing inverse transformation on the target direct axis voltage and the target quadrature axis voltage to obtain the vector voltage.

4. The method for discharging a capacitor according to any one of claims 1 to 3, further comprising:

acquiring the voltage of the capacitor;

and if the voltage is detected to be smaller than the preset voltage threshold value, ending the discharge.

5. The discharge device of a capacitor is applied to control equipment of a permanent magnet motor, and is characterized by comprising:

the acquisition module is used for acquiring a rotor position angle of the permanent magnet motor and an output current of the permanent magnet motor if a discharge instruction is received;

the determining module is used for determining the calibration voltage amplitude of the vector voltage in the vector control of the permanent magnet motor according to the output current of the permanent magnet motor and the given discharge current amplitude;

the adjusting module is used for adjusting the output voltage corresponding to the output current through the calibration voltage amplitude and the rotor position angle to obtain a target voltage;

and the control module is used for generating the vector voltage based on the target voltage so as to enable the permanent magnet motor to discharge the capacitor under the control of the target vector voltage.

6. The capacitive discharge device of claim 5, wherein the determination module is specifically configured to:

carrying out coordinate transformation on the output current to obtain alpha-axis current and beta-axis current;

calculating the alpha-axis current and the beta-axis current to obtain a feedback current amplitude;

and carrying out proportional integral control on the feedback current amplitude and the given discharge current amplitude to obtain the calibration voltage amplitude.

7. The capacitive discharge device of claim 6, wherein the adjustment module is specifically configured to:

under the constraint of the rotor position angle, carrying out coordinate decomposition on the calibration voltage amplitude to obtain a first calibration voltage and a second calibration voltage;

regulating the quadrature-axis voltage corresponding to the direct-axis current by using the first calibration voltage to obtain a target quadrature-axis voltage larger than 0;

regulating the direct axis voltage corresponding to the quadrature axis current by using the second calibration voltage to obtain a target direct axis voltage equal to 0;

the generation module is specifically configured to:

and performing inverse transformation on the target direct axis voltage and the target quadrature axis voltage to obtain the vector voltage.

8. The discharging device of any one of claims 5-7, wherein the control module is further configured to obtain a voltage of the capacitor; and if the voltage is detected to be smaller than the preset voltage threshold value, ending the discharge.

9. The discharge system of a kind of electric capacity, characterized by, including permanent-magnet machine and control equipment;

the permanent magnet motor is respectively connected with the control equipment and the capacitor;

the control device is adapted to perform a method of discharging a capacitor as claimed in any one of claims 1 to 4.

10. A storage medium having a computer program stored thereon, wherein the computer program, when executed by a controller, implements the steps of the method according to any one of claims 1 to 4.

Technical Field

The invention belongs to the technical field of capacitor discharge, and particularly relates to a capacitor discharge method, device and system and a storage medium.

Background

In a power supply system with high-power electronic equipment, such as an electric traction system, in order to stabilize the fluctuation of the intermediate voltage and achieve a certain buffering function for energy, a passive element, namely an intermediate capacitor, is often added in the power supply system. The intermediate capacitor not only can realize voltage filtering, but also can play a role in electric quantity storage. However, after the system is powered off, the middle capacitor can discharge naturally to consume the electric energy stored in the middle capacitor, but the system is still electrified in the electric energy consumption process of discharging in the middle capacitor, so that the normal use of the system is affected, and if the system is electrified, the system cannot be manually close to the maintenance.

Disclosure of Invention

The invention mainly aims to provide a capacitor discharging method, a capacitor discharging device, a capacitor discharging system and a storage medium, and aims to solve the problem that in the prior art, when a capacitor is discharged, the robustness of a permanent magnet motor in a static state is low, and the discharging reliability is poor.

In order to solve the above problem, the present invention provides a method for discharging a capacitor, which is applied to a control device of a permanent magnet motor, and comprises:

if a discharge instruction is received, acquiring a rotor position angle of the permanent magnet motor and an output current of the permanent magnet motor;

determining a calibration voltage amplitude of a vector voltage in vector control of the permanent magnet motor according to the output current of the permanent magnet motor and a given discharge current amplitude;

adjusting the output voltage corresponding to the output current through the calibration voltage amplitude and the rotor position angle to obtain a target voltage;

and generating the vector voltage based on the target voltage so that the permanent magnet motor discharges the capacitor under the control of the vector voltage.

Further, in the above capacitor discharging method, determining a calibration voltage amplitude of a vector voltage in vector control of the permanent magnet motor according to the output current of the permanent magnet motor and a given discharging current amplitude includes:

carrying out coordinate transformation on the output current to obtain alpha-axis current and beta-axis current;

calculating the alpha-axis current and the beta-axis current to obtain a feedback current amplitude;

and carrying out proportional integral control on the feedback current amplitude and the given discharge current amplitude to obtain the calibration voltage amplitude.

Further, in the above capacitor discharging method, the adjusting the output voltage corresponding to the output current by the calibration voltage amplitude and the rotor position angle to obtain a target voltage includes:

under the constraint of the rotor position angle, carrying out coordinate decomposition on the calibration voltage amplitude to obtain a first calibration voltage and a second calibration voltage;

regulating the quadrature-axis voltage corresponding to the direct-axis current by using the first calibration voltage to obtain a target quadrature-axis voltage larger than 0;

regulating the direct axis voltage corresponding to the quadrature axis current by using the second calibration voltage to obtain a target direct axis voltage equal to 0;

correspondingly, generating the vector voltage based on the target voltage comprises:

and performing inverse transformation on the target direct axis voltage and the target quadrature axis voltage to obtain the vector voltage.

Further, the above method for discharging a capacitor further includes:

acquiring the voltage of the capacitor;

and if the voltage is detected to be smaller than the preset voltage threshold value, ending the discharge.

The invention also provides a discharging device of a capacitor, which is applied to the control equipment of the permanent magnet motor and comprises:

the acquisition module is used for acquiring a rotor position angle of the permanent magnet motor and an output current of the permanent magnet motor if a discharge instruction is received;

the determining module is used for determining the calibration voltage amplitude of the vector voltage in the vector control of the permanent magnet motor according to the output current of the permanent magnet motor and the given discharge current amplitude;

the adjusting module is used for adjusting the output voltage corresponding to the output current through the calibration voltage amplitude and the rotor position angle to obtain a target voltage;

and the control module is used for generating the vector voltage based on the target voltage so as to enable the permanent magnet motor to discharge the capacitor under the control of the target vector voltage.

Further, in the above discharging device for a capacitor, the determining module is specifically configured to:

carrying out coordinate transformation on the output current to obtain alpha-axis current and beta-axis current;

calculating the alpha-axis current and the beta-axis current to obtain a feedback current amplitude;

and carrying out proportional integral control on the feedback current amplitude and the given discharge current amplitude to obtain the calibration voltage amplitude.

Further, in the above discharging device for a capacitor, the adjusting module is specifically configured to:

under the constraint of the rotor position angle, carrying out coordinate decomposition on the calibration voltage amplitude to obtain a first calibration voltage and a second calibration voltage;

regulating the quadrature-axis voltage corresponding to the direct-axis current by using the first calibration voltage to obtain a target quadrature-axis voltage larger than 0;

regulating the direct axis voltage corresponding to the quadrature axis current by using the second calibration voltage to obtain a target direct axis voltage equal to 0;

the generation module is specifically configured to:

and performing inverse transformation on the target direct axis voltage and the target quadrature axis voltage to obtain the vector voltage.

Further, in the above discharging device for a capacitor, the control module is further configured to obtain a voltage of the capacitor; and if the voltage is detected to be smaller than the preset voltage threshold value, ending the discharge.

The invention also provides a discharging system of the capacitor, which comprises a permanent magnet motor and control equipment;

the permanent magnet motor is respectively connected with the control equipment and the capacitor;

the control device is configured to perform the method of discharging a capacitance as described in any of the above valleys.

The invention also provides a storage medium having stored thereon a computer program which, when executed by a controller, carries out the steps of the method according to any one of the preceding claims.

Compared with the prior art, one or more embodiments in the above scheme can have the following advantages or beneficial effects:

according to the capacitor discharging method, device, system and storage medium, if a discharging instruction is received, the rotor position angle of the permanent magnet motor and the output current of the permanent magnet motor are obtained; and after the calibration voltage amplitude of the vector voltage in the vector control of the permanent magnet motor is determined according to the output current and the given discharge current amplitude of the permanent magnet motor, the current amplitude and the position angle corresponding to the vector voltage can be used as direct control quantities, the output voltage corresponding to the output current is adjusted, and finally the vector voltage is obtained, so that the permanent magnet motor discharges the capacitor under the control of the vector voltage. By adopting the technical scheme of the invention, the quadrature axis current is ensured to be 0 and the direct axis current is not 0 under the condition that zero drift is too large or the feedback is inaccurate in current sampling, so that the robustness of the permanent magnet motor in a static state is improved, and the discharge reliability is further improved.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a flow chart of an embodiment of a method for discharging a capacitor according to the present invention;

FIG. 2 is a schematic structural diagram of a discharging device of a capacitor according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a discharging system of a capacitor according to an embodiment of the present invention.

Detailed Description

The following detailed description of the embodiments of the present invention will be provided with reference to the drawings and examples, so that how to apply the technical means to solve the technical problems and achieve the technical effects can be fully understood and implemented. It should be noted that, as long as there is no conflict, the embodiments and the features of the embodiments of the present invention may be combined with each other, and the technical solutions formed are within the scope of the present invention.

Fig. 1 is a flow chart of an embodiment of the method for discharging a capacitor according to the invention, which is applied to a control device of a permanent magnet motor, preferably an electric traction system, so that a vehicle parking discharge can be achieved. As shown in fig. 1, the discharging method of the capacitor in this embodiment may specifically include the following steps:

100. if a discharge instruction is received, acquiring a rotor position angle of the permanent magnet motor and an output current of the permanent magnet motor;

in a specific implementation process, after the power supply system is powered off, the master control system of the power supply system generates a discharge instruction and sends the discharge instruction to the control equipment of the permanent magnet motor, so that the control equipment of the permanent magnet motor can acquire the position angle of the rotor of the permanent magnet motor and the output current of the permanent magnet motor. For example, the output current of the permanent magnet motor may be acquired by a current sensor, and the rotation speed and the rotor position angle of the rotor may be acquired by a speed sensor. In this way, the output current and rotor position angle of the permanent magnet motor can be used as input control parameters of the permanent magnet motor.

101. Determining a calibration voltage amplitude of a vector voltage in vector control of the permanent magnet motor according to the output current of the permanent magnet motor and a given discharge current amplitude;

in practical application, a user can input corresponding discharge current according to an actual discharge requirement, so that the control equipment can obtain a given discharge current amplitude value according to the discharge current to serve as an input control parameter of the permanent magnet motor. For example, a user may obtain a larger given discharge current magnitude if the user desires a fast discharge, and a smaller given discharge current magnitude if the user does not desire a fast discharge.

In a specific implementation process, the vector control of the permanent magnet motor is finally controlled by the vector voltage, so in this embodiment, after the output current of the permanent magnet motor is obtained, the coordinate transformation of the output current can be performed to obtain the α -axis current and the β -axis current. For example, Clark transformation may be performed on the output current to obtain an α -axis current and a β -axis current, and the α -axis current and the β -axis current are synthesized to obtain a feedback current amplitude capable of reflecting the output voltage of the permanent magnet motor, and proportional integral control may be performed on the feedback current amplitude and a given discharge current amplitude to obtain a calibration voltage amplitude, so that a vector voltage in vector control of the permanent magnet motor may be obtained using the obtained calibration voltage amplitude subsequently. Therefore, even if the amplitude of the obtained feedback current has deviation due to large zero drift or inaccurate sampling precision when the output current of the permanent magnet motor is sampled, the vector voltage obtained subsequently can also be ensured to be accurate data.

102. Adjusting output voltage corresponding to the output current through calibrating the voltage amplitude and the rotor position angle to obtain target voltage;

specifically, since the real current is determined by the voltage, the embodiment uses the amplitude of the calibration voltage as a control quantity, and can perform coordinate decomposition on the amplitude of the calibration voltage under the constraint of the rotor position angle to obtain a first calibration voltage and a second calibration voltage; adjusting quadrature-axis voltage corresponding to the direct-axis current by using the first calibration voltage to obtain target quadrature-axis voltage larger than 0; regulating the direct axis voltage corresponding to the quadrature axis current by using the second calibration voltage to obtain a target direct axis voltage equal to 0;

like this, because the restraint of rotor position angle, can guarantee that current magnetic field direction is unanimous with rotor magnetic field direction, and the vector voltage that will obtain is used in the permanent-magnet machine back, can make permanent-magnet machine's output current correspond the quadrature axis voltage not be 0, and permanent-magnet machine's output current corresponds the direct axis voltage be 0, thereby guarantee when sampling permanent-magnet machine's output current, even appear great zero drift or sampling precision on time, still can guarantee that the quadrature axis current is 0, the direct axis current is not 0.

Specifically, the direct axis voltage can be calculated by the calculation formula (1):

U_d＝R_si_d-w_eL_qi_q(1)

the quadrature axis voltage can be calculated by the formula (2)

L U_q＝R_si_q+ωL_di_d+ωφ_f(2)

The electromagnetic torque can be calculated by the calculation formula (3)

Wherein, U_dIs the direct axis voltage, R_sIs stator resistance, i_dIs a direct axis current, w_eIs the stator frequency, L_dIs a direct axis inductor, i_qFor quadrature currents, T_eIn order to be an electromagnetic torque,

is the rotor flux linkage.

Since the resistance of the stator resistor is very small, the resistance of the stator resistor can be recorded as 0, so that when U is calculated according to the above calculation formula_d＝0，U_qWhen not equal to 0, i is inevitable_q0 and i_dWhen not equal to 0, the corresponding output electromagnetic torque T_eTherefore, in this embodiment, the direct-axis voltage and the quadrature-axis voltage can be directly controlled to obtain the target quadrature-axis voltage greater than 0 and the target direct-axis voltage equal to 0, so as to control the direct-axis current and the quadrature-axis current, and finally, the stator current vector of the permanent magnet motor and the rotor flux linkage vector can be kept in the same direction, and the interaction between the stator current vector and the rotor flux linkage vector does not generate electromagnetic torque, that is, the motor does not shake and can be in a stationary state all the time.

103. Based on the target voltage, a vector voltage is generated so that the permanent magnet motor discharges the capacitor under the control of the target vector voltage.

Specifically, the target direct-axis voltage and the target quadrature-axis voltage may be inversely transformed to obtain a vector voltage. For example, the target direct axis voltage and the target quadrature axis voltage may be subjected to inverse Clark transformation to obtain a vector voltage. Wherein, the vector voltage can be obtained according to the calculation formula (4):

wherein, U_sAs vector voltage, U_alfaIs a target direct axis voltage, U_betaTarget quadrature axis voltage.

After the vector voltage is obtained, the permanent magnet motor can discharge the capacitor under the control of the vector voltage, so that the real zero electromagnetic torque discharge can be realized without depending on the precision of current sampling, no additional equipment is needed, the existing permanent magnet motor is used as a control object, the capacitor can be discharged, and the discharge current is adjustable.

In the discharging method of the capacitor of the embodiment, if a discharging instruction is received, a rotor position angle of a permanent magnet motor and an output current of the permanent magnet motor are obtained; and after the calibration voltage amplitude of the vector voltage in the vector control of the permanent magnet motor is determined according to the output current and the given discharge current amplitude of the permanent magnet motor, the current amplitude and the position angle corresponding to the vector voltage can be used as direct control quantities, the output voltage corresponding to the output current is adjusted, and finally the vector voltage is obtained, so that the permanent magnet motor discharges the capacitor under the control of the vector voltage. By adopting the technical scheme of the invention, the quadrature axis current is ensured to be 0 and the direct axis current is not 0 under the condition that zero drift is too large or the feedback is inaccurate in current sampling, so that the robustness of the permanent magnet motor in a static state is improved, and the discharge reliability is further improved.

Further, in the above embodiment, in the process of discharging the capacitor, the voltage of the capacitor can be obtained in real time; if the voltage of the capacitor is detected to be smaller than the preset voltage threshold, the discharging can be finished.

It should be noted that the method of the embodiment of the present invention may be executed by a single device, such as a computer or a server. The method of the embodiment can also be applied to a distributed scene and completed by the mutual cooperation of a plurality of devices. In the case of such a distributed scenario, one device of the multiple devices may only perform one or more steps of the method according to the embodiment of the present invention, and the multiple devices interact with each other to complete the method.

Fig. 2 is a schematic structural diagram of an embodiment of the discharging device of the capacitor of the present invention, which is preferably applied to a control device of a permanent magnet motor. As shown in fig. 2, the discharging device of the capacitor of the present embodiment includes an obtaining module 20, a determining module 21, an adjusting module 22, and a control module 23.

The obtaining module 20 is configured to obtain a rotor position angle of the permanent magnet motor and an output current of the permanent magnet motor if a discharging instruction is received;

the determining module 21 is configured to determine a calibration voltage amplitude of a vector voltage in vector control of the permanent magnet motor according to the output current of the permanent magnet motor and a given discharge current amplitude;

specifically, the output current is subjected to coordinate transformation to obtain an alpha-axis current and a beta-axis current; calculating the alpha-axis current and the beta-axis current to obtain a feedback current amplitude; and carrying out proportional integral control on the feedback current amplitude and the given discharge current amplitude to obtain a calibration voltage amplitude. The adjusting module 22 is configured to adjust an output voltage corresponding to the output current by calibrating the voltage amplitude and the rotor position angle to obtain a target voltage;

specifically, under the constraint of a rotor position angle, coordinate decomposition is carried out on a calibration voltage amplitude to obtain a first calibration voltage and a second calibration voltage; adjusting quadrature-axis voltage corresponding to the direct-axis current by using the first calibration voltage to obtain target quadrature-axis voltage larger than 0; and regulating the direct axis voltage corresponding to the quadrature axis current by using the second calibration voltage to obtain a target direct axis voltage equal to 0.

And the control module 23 is configured to generate a vector voltage based on the target voltage, so that the permanent magnet motor discharges the capacitor under the control of the target vector voltage.

Specifically, inverse transformation is performed on the target direct axis voltage and the target quadrature axis voltage to obtain a vector voltage.

In the discharging device of the capacitor of the embodiment, if a discharging instruction is received, the rotor position angle of the permanent magnet motor and the output current of the permanent magnet motor are obtained; and after the calibration voltage amplitude of the vector voltage in the vector control of the permanent magnet motor is determined according to the output current and the given discharge current amplitude of the permanent magnet motor, the current amplitude and the position angle corresponding to the vector voltage can be used as direct control quantities, the output voltage corresponding to the output current is adjusted, and finally the vector voltage is obtained, so that the permanent magnet motor discharges the capacitor under the control of the vector voltage. By adopting the technical scheme of the invention, the quadrature axis current is ensured to be 0 and the direct axis current is not 0 under the condition that zero drift is too large or the feedback is inaccurate in current sampling, so that the robustness of the permanent magnet motor in a static state is improved, and the discharge reliability is further improved.

Further, in the above embodiment, the control module 23 is further configured to obtain a voltage of the capacitor; and if the voltage is detected to be smaller than the preset voltage threshold value, ending the discharge.

It should be noted that the apparatus in the foregoing embodiment is used for implementing the corresponding method in the foregoing embodiment, and has the beneficial effects of the corresponding method embodiment, which are not described herein again.

Fig. 3 is a schematic structural diagram of an embodiment of a discharging system of a capacitor according to the present invention, and as shown in fig. 3, the discharging system of the capacitor according to the present embodiment includes a permanent magnet motor 30 and a control device 31; wherein the permanent magnet motor 30 is connected with the control device 31 and the capacitor, respectively. The control device 31 is used to execute the discharging method of the capacitance of the above-described embodiment.

In order to solve the above technical problems in the prior art, embodiments of the present invention provide a storage medium.

The storage medium provided by the embodiment of the invention stores a computer program thereon, and the computer program realizes the steps of the method when being executed by a processor.

It is understood that the same or similar parts in the above embodiments may be mutually referred to, and the same or similar parts in other embodiments may be referred to for the content which is not described in detail in some embodiments.

It should be noted that the terms "first," "second," and the like in the description of the present invention are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Further, in the description of the present invention, the meaning of "a plurality" means at least two unless otherwise specified.

Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps of the process, and alternate implementations are included within the scope of the preferred embodiment of the present invention in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present invention.

It should be understood that portions of the present invention may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or combination of the following techniques, which are known in the art, may be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or the like.

It will be understood by those skilled in the art that all or part of the steps carried by the method for implementing the above embodiments may be implemented by hardware related to instructions of a program, which may be stored in a computer readable storage medium, and when the program is executed, the program includes one or a combination of the steps of the method embodiments.

In addition, each functional unit in the embodiments of the present invention may be integrated in one processing module 32, or each unit may exist alone physically, or two or more units are integrated in one module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. The integrated module, if implemented in the form of a software functional module and sold or used as a stand-alone product, may also be stored in a computer readable storage medium.

The storage medium mentioned above may be a read-only memory, a magnetic or optical disk, etc.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been described above, the above description is only for the convenience of understanding the present invention, and is not intended to limit the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.