Control method and device of cruise control system, controller and vehicle

[0073] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0074] See figure 1 The embodiment of the present invention provides a control method of a cruise control system, which is applied to a controller of the cruise control system, and the controller is a motor controller MCU or a vehicle controller VCU.

[0075] As a first example, see figure 2 , figure 2 It is the specific structure of the cruise control system, where the control module A is the controller in the embodiment of the present invention, and the controller is a motor controller (Moter Control Unit, MCU) or a vehicle controller (Vehicle Control Unit, VCU);

[0076] Among them, the Electronic Stability Program (ESP), the Intelligent Combination Meter (ICM), the vehicle controller, the Electronic Park Brake (EPB), and the Antilock Brake System (ABS) ) And the control module A are connected through the CAN bus. The cruise switch group outputs the cruise switch signal to the control module A; the accelerator pedal outputs the accelerator pedal signal to the control module A; the brake switch outputs the brake switch signal and the brake light signal to the control module A.

[0077] Among them, the shifter is connected to the control module A through the control module B. Specifically, the mapping relationship between the control module B and the control module A can be represented by Table 1:

[0078] Table 1:

[0079] Vehicle architecture Control module A Control module B State 1 VCU VCU State 2 MCU VCU State 3 MCU MCU

[0080] It should be noted that when the control module A and the control module B are mapped to the same controller, the interaction signals between the two are not considered.

[0081] The three architectures in Table 1 above are the main architecture forms of the existing cruise control system. The control method of the cruise control system in the embodiment of the present invention is applicable to the above three architectures. In state 1, the VCU completely assumes the torque control function; in state 2, part of the VCU functions are undertaken by the MCU, such as acceleration and brake pedal signal collection; in state 3, the MCU completely replaces the VCU.

[0082] Specifically, see figure 1 The control method of the cruise control system provided by the embodiment of the present invention includes:

[0083] Step 101: It is monitored whether the car is currently in a constant speed cruise driving state.

[0084] Among them, the working state of the cruise control system includes a closed state, a standby state, and an active state; the car is currently in a cruise control state, and the corresponding state of the cruise control system is an active state.

[0085] Step 102: When the car is in the cruise control state, receive operation trigger information for operating the cruise switch group of the cruise control system; the operation trigger information includes start information used to start the cruise control or set the cruise target speed Reset information.

[0086] Among them, most of the cruise control system includes a cruise switch group, which can be a push-button switch or a lever switch. When the car is in the cruise control state, it receives the operation trigger information from the cruise switch group. Among them, the start information is mostly used to start the cruise control system to enter the active state. Even if the vehicle enters the cruise control state, the reset information is mostly used to set the cruise control. The cruise target vehicle speed during cruise; when the car is cruising at a fixed speed, the functions of the button or lever position corresponding to the start information and the reset information are single. In the embodiment of the present invention, the controller is made to respond to both to increase the cruise control The function of the system realizes the diversification of key functions and enhances the user experience.

[0087] Step 103: According to preset correspondences between different operation trigger information and corresponding adjustment modes, the adjustment mode corresponding to the operation trigger information is adopted to adjust the cruise target vehicle speed during the current cruise driving process.

[0088] Among them, according to the corresponding relationship between the preset trigger information and the corresponding adjustment mode, the adjustment mode corresponding to the operation trigger information is determined to adjust the cruise target speed; in this way, the vehicle can be cruised at a constant speed according to User needs or adjust the cruise target speed according to the current actual speed to improve the comfort, stability and safety of the car.

[0089] Preferably, step 103 includes:

[0090] When the operation trigger information is start information, obtain the difference between the current vehicle speed and the cruise target vehicle speed and the first duration of the operation signal of the start information;

[0091] According to the difference between the current vehicle speed and the cruise target vehicle speed and the first duration, the cruise target vehicle speed is adjusted.

[0092] Specifically, when the operation trigger information is start information, that is, when the user presses the start button or dials to the start position, the first duration of the start information and the difference between the current vehicle speed and the cruise target vehicle speed are acquired; according to the difference And the first duration, adjust the cruise target speed.

[0093] Preferably, the step of adjusting the cruise target vehicle speed according to the difference between the current vehicle speed and the cruise target vehicle speed and the first duration includes:

[0094] When the first duration is lower than the first preset duration, if the cruise target vehicle speed is higher than the current vehicle speed by a value greater than the first preset value, then the cruise target vehicle speed value is adjusted to the current vehicle speed value;

[0095] Otherwise, the cruise target vehicle speed is reduced by the second preset value.

[0096] Among them, the first duration is lower than the first preset duration, that is, the button corresponding to the short-closing start information. When the current vehicle speed does not match the cruise target vehicle speed and the trigger information of the button corresponding to the short-closing start information is received, if the cruise target vehicle speed is If the value higher than the current vehicle speed is greater than the first preset value, the value of the cruise target vehicle speed is adjusted to the value of the current vehicle speed, that is, the current vehicle speed is set as the new cruise target vehicle speed. Specifically, when the cruise target vehicle speed is higher than the current vehicle speed by a value greater than the first preset value, it indicates that the cruise target vehicle speed is set higher and has a large gap with the current vehicle speed. The current vehicle speed may not reach the cruise target speed, so reduce the cruise in time Target vehicle speed to improve driving safety. If the value of the cruise target vehicle speed higher than the current vehicle speed is not greater than the first preset value, it indicates that the difference between the two is not large, and the cruise target vehicle speed only needs to be reduced by the second preset value. It should be noted that if the adjusted cruise target vehicle speed is lower than the preset minimum value of the cruise speed range, the vehicle will be exited from cruise control.

[0097] Among them, the first preset value and the second preset value can be preset.

[0098] Preferably, the step of adjusting the cruise target vehicle speed according to the difference between the current vehicle speed and the cruise target vehicle speed and the first duration includes:

[0099] When the first duration exceeds the second preset duration, within the first duration,

[0100] If the current vehicle speed is higher than the cruise target vehicle speed value and greater than the third preset value, then the current vehicle speed is set as the cruise target vehicle speed, and the cruise target vehicle speed is reduced according to the first preset speed;

[0101] Otherwise, the cruise target vehicle speed is reduced according to the second preset speed.

[0102] Wherein, when the first duration exceeds the second preset duration, that is, when the button corresponding to the normally closed short-closed start message, within the first duration, if the current vehicle speed is higher than the cruise target vehicle speed value is greater than the third preset value , If the current vehicle speed is higher than the cruise target speed value and greater than the third preset value, the cruise target vehicle speed value is adjusted to the current vehicle speed value, and the cruise target vehicle speed is reduced according to the first preset speed; that is, the current vehicle speed is set to The new cruise target speed, and gradually reduce the new cruise target speed. Specifically, when the current vehicle speed is higher than the cruise target vehicle speed value greater than the third preset value, it indicates that the current vehicle speed is higher, and the current vehicle speed is far from the current vehicle speed. The current vehicle speed may not be reduced to the cruise target vehicle speed in a short time. Set the vehicle speed to the new cruise target speed and gradually reduce the cruise target speed to improve driving safety. If the current vehicle speed is higher than the cruise target vehicle speed value is not greater than the third preset value, it indicates that there is not much difference between the two, and it only needs to be reduced according to the second preset speed. It should be noted that if the adjusted cruise target vehicle speed is lower than the preset minimum value of the cruise speed range, the vehicle will be exited from the cruise control.

[0103] Preferably, step 103 includes:

[0104] When the operation trigger information is reset information, acquiring the second duration of the operation signal of the reset information;

[0105] According to the second duration, the cruise target vehicle speed is adjusted.

[0106] Specifically, when the operation trigger information is reset information, that is, when the user presses the reset button or dials to the reset position, the second duration of the reset information is acquired, and the cruise target vehicle speed is adjusted according to the second duration.

[0107] Preferably, the step of adjusting the cruise target vehicle speed according to the second duration includes:

[0108] When the second duration is lower than the third preset duration, the cruise target vehicle speed is increased by a fourth preset value.

[0109] Specifically, when the second duration is lower than the third preset duration, that is, when the reset button is closed shortly, the cruise target vehicle speed is directly increased by the fourth preset value.

[0110] Preferably, the step of adjusting the cruise target vehicle speed according to the second duration includes:

[0111] When the second duration exceeds the fourth preset duration, the cruise target vehicle speed is increased according to the third preset rate within the second duration.

[0112] Wherein, when the second duration exceeds the fourth preset duration, that is, when the normally closed reset button is pressed, the cruise target vehicle speed is gradually increased according to the third preset rate.

[0113] It should be noted that if the adjusted cruise target vehicle speed is higher than the preset maximum value of the cruise speed range, the cruise target vehicle speed is readjusted to the preset maximum value of the cruise speed range.

[0114] Preferably, after step 101, the method further includes;

[0115] When the car is in the cruise control state, obtain the current cruise target vehicle speed during the cruise;

[0116] When the cruise target vehicle speed is higher than the maximum value of the preset cruise speed range, adjust the cruise target vehicle speed to the maximum value of the preset cruise speed range; and/or

[0117] When the cruise target vehicle speed is lower than the preset minimum value of the cruise speed range, the cruise target vehicle speed is adjusted to the preset minimum value of the cruise speed range.

[0118] Among them, when the car is cruising, the cruise target speed is monitored in real time. If the cruise target speed is higher than the preset maximum value of the cruise speed range, the speed may be too high, which may affect the driving safety, then the cruise target speed will be adjusted Is the maximum value; and when the cruise target vehicle speed is lower than the preset minimum value of the cruise speed range, the cruise target vehicle speed is adjusted to the minimum value or the cruise control is exited.

[0119] Preferably, after step 101, the method further includes:

[0120] When it is detected that the car has not received an acceleration signal, and the current vehicle speed is higher than the cruise target speed value reaches the sixth preset value, and the duration exceeds the fifth preset duration;

[0121] When it is detected that the value of the cruise target vehicle speed higher than the current vehicle speed reaches the seventh preset value, and the duration exceeds the sixth preset duration; and/or

[0122] When the acceleration pedal torque of the detected car exceeds the preset cruising demand torque value and exceeds the fifth preset value,

[0123] Stop cruising at a constant speed.

[0124] Among them, when the car is cruising at a constant speed, if there is no acceleration signal, the value of the current vehicle speed higher than the cruise target speed reaches the sixth preset value, and the duration exceeds the fifth preset duration, indicating that the current vehicle speed is abnormal. In order to ensure driving safety, it is necessary to exit the cruise control; and when it is detected that the cruise target vehicle speed is higher than the current vehicle speed and reaches the seventh preset value, and the duration exceeds the sixth preset time, it indicates that the current vehicle speed is low. When the vehicle speed is abnormal; and when the accelerator pedal torque is higher than the preset cruising demand torque and the value exceeds the fifth preset value, it indicates that the difference between the accelerator pedal torque and the cruising demand torque is large, and there may be an abnormality. In order to ensure driving safety, you need to exit Cruise at a constant speed.

[0125] Preferably, after step 101, the method further includes:

[0126] When the car is in the cruise state, the state signal of the electronic stability system of the car is detected to indicate that there is a torque interference request, and/or the state signal of the gear of the car indicates that the gear of the car is not in the forward gear, stop the constant speed Cruising.

[0127] Among them, when the status signal of the electronic stability system is detected to indicate that there is a torque interference request, the electronic stability system may be in abnormal state or the current car torque is abnormal, and the gear is not in forward gear during driving, indicating that the driving is abnormal; the above conditions should be timely Launched cruise control.

[0128] As a second example, still take figure 2 Take the cruise control system in China as an example, where image 3 It is the conversion relationship between the three working states of the cruise control system, in which the closed state indicates that the system is off; the alternate state indicates that the system is powered on but the cruise is not performed; the active state indicates that the car enters the cruise state.

[0129] Among them, the key corresponding to the start information in the cruise switch group is the SET key, and the key corresponding to the reset information is the RES key.

[0130] Specifically, when the cruise control system is activated, if the control module A detects that the SET button is short-closed, it will deal with the following two situations:

[0131] (1) When the difference between the current vehicle speed and the cruise target vehicle speed is greater than a certain value (calibrated), set the current vehicle speed as the cruise target vehicle speed;

[0132] (2) Otherwise, the cruise target vehicle speed is reduced by ΔV1 (for example, 1km/h, which can be calibrated). If the reduced cruise target vehicle speed is lower than Vccmin (the minimum value of the cruise speed range), the cruise function exits the active state.

[0133] When the cruise control system is activated, if the control module A detects the long-closed SET button, it will deal with the following two situations:

[0134] (1) When the difference between the current vehicle speed and the cruise target vehicle speed is greater than a certain value (calibrated), the cruise target vehicle speed is set to the current vehicle speed and reduced at a certain speed (for example, a decrease of 1km/h every 0.5s can be calibrated). If the reduced cruise target vehicle speed is lower than Vccmin, the cruise function will exit the active state;

[0135] (2) Otherwise, the cruise target vehicle speed will be reduced according to a certain speed (for example, 1km/h every 0.5s, which can be calibrated). If the reduced cruise target vehicle speed is lower than Vccmin, the cruise function exits the active state.

[0136] When the cruise control system is activated, if the control module A detects that the RES button is closed shortly, the cruise target vehicle speed will increase by ΔV2 (for example, 1km/h, which can be calibrated). If the increased cruise target vehicle speed is higher than Vccmax (the maximum value of the cruise speed range), the cruise target vehicle speed is set to Vccmax.

[0137] In the active state of the cruise control system, if the control module A detects that the RES button is closed for a long time, the cruise target vehicle speed will increase at a certain speed (for example, a decrease of 1km/h every 0.5s, which can be calibrated). If the increased cruise target vehicle speed is higher than Vccmax, the cruise target vehicle speed is set to Vccmax.

[0138] Optionally, see image 3 , For the switching between the working status of the cruise control system, as follows:

[0139] (1) Switch from closed state to standby state:

[0140] When it is detected that the current state of the car meets the first preset condition, the working state of the cruise control system is switched from the off state to the standby state; among them,

[0141] The first preset condition at least includes: a power-on signal of the cruise control system is detected and a fault signal of the cruise control system is not detected.

[0142] (2) Switch from standby state to closed state:

[0143] When it is detected that the current state of the car meets the second preset condition, the working state of the cruise control system is switched from the standby state to the off state; among them,

[0144] The second preset condition includes: detecting at least one of a power-off signal of the cruise control system and a detected fault signal of the cruise control system.

[0145] (3) Switch from standby state to active state:

[0146] When it is detected that the current state of the car meets the third preset condition, the working state of the cruise control system is switched from the standby state to the active state; among them,

[0147] The third preset condition includes at least: the start signal of the cruise control system is detected, the gear of the car is in forward gear, the current vehicle speed is in the preset cruise speed range, the brake signal is not detected, and the electronic stability is not detected The torque interference request of the system and the failure signal of the cruise control system is not detected.

[0148] (4) Switch from active state to standby state:

[0149] When it is detected that the current state of the car meets the fourth preset condition, the working state of the cruise control system is switched from the active state to the standby state; among them,

[0150] The fourth preset conditions include:

[0151] The exit signal of the active state of the cruise control system is detected;

[0152] The gear of the car is not in forward gear;

[0153] The current vehicle speed is higher than the preset maximum value of the cruise speed range and exceeds the first value;

[0154] The current vehicle speed is lower than the preset minimum cruise speed range and exceeds the first value;

[0155] No acceleration signal is detected and the current vehicle speed is higher than the current cruise target vehicle speed of the cruise control system and the duration reaches the first duration;

[0156] The current vehicle speed is lower than the current cruise target vehicle speed exceeds the second value and the duration reaches the second duration;

[0157] The current accelerator pedal torque is higher than the preset cruise demand torque and exceeds the first preset torque and the duration reaches the third duration;

[0158] The brake signal is detected;

[0159] The torque interference request of the electronic stability system is detected;

[0160] It is detected that the current cruise target vehicle speed is lower than the minimum value of the cruise speed range;

[0161] It is detected that the electronic parking system is in the enabled state;

[0162] And at least one of the fault signals of the cruise control system is detected.

[0163] (5) Switch from active state to closed state:

[0164] When it is detected that the current state of the car meets the fifth preset condition, the working state of the cruise control system is switched from the active state to the off state; among them,

[0165] The fifth preset condition includes: detecting a power-off signal of the cruise control system.

[0166] Optionally, the failure signal of the aforementioned cruise control system includes:

[0167] The cruise switch group of the cruise control system is faulty, the brake signal of the car is faulty, the accelerator pedal signal of the car is faulty, the speed signal of the car is faulty, the electronic stability system of the car is faulty, the electronic stability system of the car is communication fault, and the anti-lock brake of the car At least one of a system failure, a communication failure of the anti-lock braking system of the automobile, and a communication failure of the electronic parking system of the automobile.

[0168] Optionally, when the cruise control system is active, the control module A should calculate the cruise demand torque based on the vehicle speed and output the cruise demand torque to the MCU.

[0169] In the above-mentioned embodiment of the present invention, by detecting the constant-speed cruise driving state of the car, when receiving the operation trigger information of the cruise switch group, the adjustment method for adjusting the cruise target vehicle speed is determined according to different operation trigger information, and the cruise target vehicle speed is adjusted ; In this way, when the vehicle is cruising at a constant speed, the cruise target speed can be adjusted according to user needs or according to the current actual vehicle speed to improve the comfort, stability and safety of the vehicle. By adding multiple adjustment modes corresponding to the start information and the reset information, the present invention increases the key function of the keys corresponding to the start information and the reset information, and adds the adjustment mode of the cruise target vehicle speed during the car's constant speed cruise; And during the adjustment process, it is adjusted based on the current actual vehicle speed to improve the safety of the car during driving. The control method provided by the present invention is applicable to the architecture of multiple cruise control systems, realizes the platformization and integrated control of the cruise control system, and improves the versatility of the program code. The present invention solves the problem that the key function of the cruise switch group of the existing cruise control system is relatively single, and the target vehicle speed under the cruise control state has fewer adjustment methods, and it is difficult to meet the user's needs.

[0170] See Figure 4 An embodiment of the present invention also provides a control device for a cruise control system, the control device is a motor controller MCU or a vehicle controller VCU, and the device includes:

[0171] The monitoring module 401 is used to monitor whether the car is currently in a cruise state.

[0172] Among them, the working state of the cruise control system includes a closed state, a standby state, and an active state; the car is currently in a cruise control state, and the corresponding state of the cruise control system is an active state.

[0173] The receiving module 402 is used to receive the operation trigger information for operating the cruise switch group of the cruise control system when the car is in the cruise control state; the operation trigger information includes start information for starting the cruise control or for setting The reset information of the cruise target speed.

[0174] Among them, most of the cruise control system includes a cruise switch group, which can be a push-button switch or a lever switch. When the car is in the cruise control state, it receives the operation trigger information from the cruise switch group. Among them, the start information is mostly used to start the cruise control system to enter the active state. Even if the vehicle enters the cruise control state, the reset information is mostly used to set the cruise control. The cruise target vehicle speed during cruise; when the car is cruising at a fixed speed, the functions of the button or lever position corresponding to the start information and the reset information are single. In the embodiment of the present invention, the controller is made to respond to both to increase the cruise control The function of the system realizes the diversification of key functions and enhances the user experience.

[0175] The adjustment module 403 is configured to adjust the cruise target vehicle speed during the current cruise driving process by adopting an adjustment method corresponding to the operation trigger information according to preset correspondences between different operation trigger information and corresponding adjustment modes.

[0176] Among them, according to the corresponding relationship between the preset trigger information and the corresponding adjustment mode, the adjustment mode corresponding to the operation trigger information is determined to adjust the cruise target vehicle speed; in this way, the vehicle can be cruised at a constant speed according to User needs or adjust the cruise target speed according to the current actual speed to improve the comfort, stability and safety of the car.

[0177] Preferably, the adjustment module 403 includes:

[0178] The first acquisition sub-module is used to acquire the difference between the current vehicle speed and the cruise target vehicle speed and the first duration of the operation signal of the start information when the operation trigger information is start information;

[0179] The first adjustment submodule is used to adjust the cruise target vehicle speed according to the difference between the current vehicle speed and the cruise target vehicle speed and the first duration.

[0180] Preferably, the first adjustment submodule includes:

[0181] The first adjustment unit is configured to adjust the value of the cruise target vehicle speed to the value of the current vehicle speed if the cruise target vehicle speed is higher than the current vehicle speed by a value greater than the first preset value when the first duration is lower than the first preset duration Numerical value

[0182] Otherwise, the cruise target vehicle speed is reduced by the second preset value.

[0183] Preferably, the first adjustment submodule includes:

[0184] The second adjustment unit is configured to, when the first duration exceeds the second preset duration, within the first duration,

[0185] If the current vehicle speed is higher than the cruise target vehicle speed value greater than the third preset value, the current vehicle speed is set as the cruise target vehicle speed, and the cruise target vehicle speed is reduced according to the first preset speed;

[0186] Otherwise, the cruise target vehicle speed is reduced according to the second preset speed.

[0187] Preferably, the adjustment module 403 includes:

[0188] The second acquisition submodule is used to acquire the second duration of the operation signal of the reset information when the operation trigger information is the reset information;

[0189] The second adjustment sub-module is used to adjust the cruise target vehicle speed according to the second duration.

[0190] Preferably, the second adjustment submodule is used for:

[0191] When the second duration is lower than the third preset duration, the cruise target vehicle speed is increased by a fourth preset value.

[0192] Preferably, the second adjustment submodule is used for:

[0193] When the second duration exceeds the fourth preset duration, during the second duration, the cruise target vehicle speed is increased according to the third preset rate.

[0194] Preferably, the device further includes:

[0195] Speed ​​monitoring module, used to obtain the current cruise target vehicle speed in the process of constant speed cruising when the car is in constant speed cruising;

[0196] When the cruise target vehicle speed is higher than the maximum value of the preset cruise speed range, adjust the cruise target vehicle speed to the maximum value of the preset cruise speed range; and/or

[0197] When the cruise target vehicle speed is lower than the minimum value of the preset cruise speed range, the cruise target vehicle speed is adjusted to the preset minimum value of the cruise speed range.

[0198] Preferably, the device further includes:

[0199] The first state monitoring module is used when it is detected that the car has not received an acceleration signal, and the value of the current vehicle speed higher than the cruise target vehicle speed reaches the sixth preset value, and the duration exceeds the fifth preset duration;

[0200] When it is detected that the value of the cruise target vehicle speed higher than the current vehicle speed reaches the seventh preset value, and the duration exceeds the sixth preset duration; and/or

[0201] When the acceleration pedal torque of the detected car exceeds the preset cruising demand torque value and exceeds the fifth preset value,

[0202] Stop cruising at a constant speed.

[0203] Preferably, the device further includes:

[0204] The second state monitoring module is used to detect that the state signal of the electronic stability system of the car indicates that there is a torque interference request when the car is in the cruise state, and/or the state signal of the gear of the car indicates the gear of the car When not in forward gear, stop the cruise control.

[0205] In the above-mentioned embodiment of the present invention, by detecting the constant-speed cruise driving state of the car, when receiving the operation trigger information of the cruise switch group, the adjustment method for adjusting the cruise target vehicle speed is determined according to different operation trigger information, and the cruise target vehicle speed is adjusted ; In this way, in the state of the vehicle cruising at a constant speed, the cruise target vehicle speed can be adjusted according to user needs or according to the current actual vehicle speed to improve the comfort, stability and safety of the vehicle. The present invention solves the problem that the key function of the cruise switch group of the existing cruise control system is relatively single, and the target vehicle speed under the cruise control state has fewer adjustment methods, and it is difficult to meet the user's needs.

[0206] In order to achieve the above objective, the embodiments of the present invention also provide a controller, including a memory, a processor, and a computer program stored on the memory and running on the processor. The processor reads the program in the memory and executes the above Steps in the method.

[0207] In order to achieve the above objective, an embodiment of the present invention also provides an automobile including the above controller.

[0208] In the above-mentioned embodiments of the present invention, in the state of constant speed cruising of the vehicle, the cruise target vehicle speed can be adjusted according to user requirements or according to the current actual vehicle speed, so as to improve the comfort, stability and safety of the vehicle. By adding multiple adjustment modes corresponding to the start information and the reset information, the present invention increases the key function of the keys corresponding to the start information and the reset information, and adds the adjustment mode of the cruise target vehicle speed during the car's constant speed cruise; And during the adjustment process, it is adjusted based on the current actual vehicle speed to improve the safety of the car during driving. The control method provided by the present invention is applicable to the architecture of multiple cruise control systems, realizes platform-based and integrated control of the cruise control system, and improves the versatility of program codes.

[0209] The above are the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principles of the present invention, several improvements and modifications can be made, and these improvements and modifications are also It should be regarded as the protection scope of the present invention.