A method and system for realizing variable power demand of tractor traction load

Abstract

The present invention discloses a method and system for realizing power demand with tractor traction load variation. According to the vehicle speed, the status flag bit, the status flag bit for judging the static transmission output power, and the status flag bit for judging the static transmission output torque, the increasing control status value of the power demand integrator and the status value of the integrator under the flag bit status of the decreasing logic control of the power demand integrator are obtained; the control status values in different working modes are calculated according to the status of the vehicle speed judgment status flag bit; the sum of the increasing control status value of the demand integrator, the status value of the integrator under the flag bit status of the decreasing logic control, and the control status values in different working modes is calculated to obtain the change rate of the integral power demand. The change rate of the power demand is compensated, and the output power demand is equal to the change rate of the compensated power demand multiplied by the operation cycle and continuously accumulated, achieving more accurate power matching in different working modes and balancing the vehicle dynamic performance and economic performance.

Description

Technical Field

[0001] The present invention belongs to the field of tractor output power distribution control, and particularly relates to a method and system for realizing power requirements under changing traction loads of a tractor. Background Art

[0002] The output power of a whole vehicle is one of the basic items for evaluating the comprehensive performance of a vehicle. Large-horsepower tractors have large horsepower and strong power performance. By controlling the output power, the power performance of the vehicle can be evaluated. However, at present, the power requirement control and matching of large-horsepower tractors are relatively single. Although they have strong power performance, they cannot take into account the vehicle economy under multiple working modes. The power matching between the engine of a large-horsepower tractor, the mechanical hydraulic transmission, and the rear axle has become a problem of tractor power distribution. Summary of the Invention

[0003] The purpose of the present invention is to provide a method and system for realizing power requirements under changing traction loads of a tractor to overcome the deficiencies of the prior art.

[0004] A method for realizing power requirements under changing traction loads of a tractor includes the following steps:

[0005] S1. Obtain the increased control state value of a power requirement integrator according to the vehicle speed judgment status flag bit, the static transmission output power judgment status flag bit, and the static transmission output torque judgment status flag bit;

[0006] S2. Obtain the state value of the integrator under the flag bit state of the power requirement integrator reduction logic control;

[0007] S3. Calculate the control state value under different working modes according to the vehicle speed judgment status flag bit state;

[0008] S4. Calculate the change rate of the integral power requirement according to the sum of the increased control state value of the requirement integrator, the state value of the integrator under the flag bit state of the reduction logic control, and the control state value under different working modes. Compensate the change rate of the power requirement according to the power compensation signal flag bit. The finally output power requirement is equal to the compensated change rate of the power requirement multiplied by the operation cycle and continuously accumulated and summed.

[0009] Preferably, the vehicle speed judgment status flag bit, the static transmission output power judgment status flag bit, and the static transmission output torque judgment status flag bit are set to 1 when set and 0 when cleared.

[0010] Preferably, if the actual vehicle speed is less than the requested vehicle speed minus the maximum allowable deviation of the requested vehicle speed before the power integrator is activated, the static transmission output power is positive power and the static transmission output power is greater than the difference between the feedforward power demand and the allowable power increase, the vehicle speed judgment status flag bit is set to 1. If any one of them is not satisfied, the vehicle speed judgment flag bit is set to 0.

[0011] Preferably, if the requested engine speed does not reach the desired engine speed corresponding to the maximum increased power of the static transmission integrator, the status value of the power demand integrator is 0, the static transmission output power is positive power, and at the same time the static transmission output power is greater than the engine power demand plus the hysteresis power for increasing the engine power, the static transmission output power judgment status flag bit is set to 1; otherwise the static transmission output power judgment flag bit is set to 0.

[0012] Preferably, when the above conditions are all satisfied, the flag bit is set to 1 after a delay of T1 seconds through the delay time.

[0013] Preferably, if the vehicle acceleration is less than the vehicle acceleration corresponding to the maximum increased torque of the static transmission integrator, the requested engine speed is less than the desired engine speed corresponding to the maximum increased torque of the static transmission integrator, the static transmission output torque exceeds the limit torque, the actual vehicle speed is less than the requested vehicle speed minus the speed difference threshold and there is no gear change at the same time, the static transmission output torque judgment flag bit is set to 1; otherwise the static transmission output torque judgment flag bit is set to 0.

[0014] Preferably, if the engine power demand is greater than the feedforward power demand, the static transmission output power is less than the difference between the engine power and the allowable power increase, the actual vehicle speed is greater than the requested vehicle speed minus the maximum allowable deviation, and at the same time the engine is not in the thrust state, the flag bit of the power demand integrator is set to 1, and the status value of the output integrator is -1; otherwise the status value of the output integrator is 0.

[0015] Preferably, the working modes include an automatic mode, a forced downshift mode, and a PTO mode;

[0016] In the automatic mode, if the vehicle speed judgment flag bit is set to 1, the control status value of the output integrator is 1; if the static transmission output power judgment flag bit or the static transmission output torque judgment flag bit is set to 1, the control status value of the output integrator is 1; if the vehicle speed judgment flag bit, the static transmission output power judgment flag bit, and the static transmission output torque judgment flag bit are all set to 0 at the same time, the control status value of the output integrator is 0;

[0017] If a forced downshift mode signal is detected, switch to the forced downshift mode. If the forced downshift mode signal flag bit is set to 1, the output integrator status value is 2; otherwise, the output integrator status value is 0. If the requested vehicle speed is 0, switch from the forced downshift mode to the automatic mode, and the output integrator status value is 0.

[0018] If it is detected that the PTO mode activation signal flag bit is 1, switch from the automatic mode or the forced downshift mode to the PTO mode, then the power demand integrator fails, and the output integrator status value is -1. If it is detected that the PTO activation signal flag bit is 0, switch back to the automatic mode again, and the output integrator status value is 0.

[0019] Preferably, when the integrator status value is -1, the change rate of power demand is dp1; when the integrator status value is 0, the change rate of power demand is dp2; when the integrator status value is 1 or 2, the change rate of power demand is dp3.

[0020] A system for realizing the power demand of a tractor traction load change includes an increasing control module of the power demand integrator, a decreasing control module of the power demand integrator, a status control module of the power demand integrator in different working modes, an integration control module of the power demand integrator, and a power compensation control module.

[0021] The increasing control module of the power demand integrator obtains the increasing control status value of the power demand integrator according to the vehicle speed judgment status flag bit, the static gearbox output power judgment status flag bit, and the static gearbox output torque judgment status flag bit.

[0022] The decreasing control module of the power demand integrator obtains the status value of the integrator under the flag bit status of the power demand integrator decreasing logic control.

[0023] The status control module of the power demand integrator in different working modes calculates the control status value in different working modes according to the vehicle speed judgment status flag bit status.

[0024] The integration control module of the power demand integrator calculates the change rate of the integrated power demand according to the sum of the increasing control status value of the demand integrator, the status value of the integrator under the flag bit status of the decreasing logic control, and the control status value in different working modes.

[0025] The power compensation control module compensates the change rate of the power demand according to the power compensation signal flag bit. The finally output power demand is equal to the compensated change rate of the power demand multiplied by the operation cycle and continuously accumulated.

[0026] Compared with the prior art, the present invention has the following beneficial technical effects:

[0027] A method for realizing the power demand of a tractor traction load change. According to the vehicle speed judgment status flag bit, the static gearbox output power judgment status flag bit, and the static gearbox output torque judgment status flag bit, obtain the increased control status value of the power demand integrator; then, according to the status value of the integrator under the flag bit status of the power demand integrator reduction logic control; and calculate the control status value in different working modes according to the status of the vehicle speed judgment status flag bit. According to the sum of the increased control status value of the demand integrator, the status value of the integrator under the flag bit status of the reduction logic control, and the control status value in different working modes, calculate the change rate of the integral power demand, compensate the change rate of the power demand according to the power compensation signal flag bit, and finally output the power demand equal to the change rate of the compensated power demand multiplied by the operation cycle and continuously accumulate and sum. The present invention realizes more precise power matching in different working modes and balances the vehicle's power performance and economic performance.

[0028] Further, according to the judgment of the vehicle speed judgment status flag bit, the static gearbox output power judgment status flag bit, and the static gearbox output torque judgment status flag bit, and the demand change of the tractor traction load in different states, reasonable allocation is realized.

[0029] Further, according to the vehicle feedforward power demand feedback, real-time feedback update can be realized, making the power distribution of the tractor more reasonable. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic structural diagram of the control system of the tractor power demand integrator in the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0032] A method for realizing the power demand of a tractor traction load change includes the following steps:

[0033] S1. According to the vehicle speed judgment status flag bit, the static gearbox output power judgment status flag bit, and the static gearbox output torque judgment status flag bit, obtain the increased control status value of the power demand integrator;

[0034] S2. Obtain the status value of the integrator under the flag bit status of the power demand integrator reduction logic control;

[0035] S3. Calculate the control state value in different working modes according to the status of the vehicle speed judgment status flag bit.

[0036] S4. Calculate the change rate of the integrated power demand based on the sum of the control state value increased by the demand integrator, the status value of the integrator under the flag bit of the reduction logic control, and the control state value in different working modes. Compensate the change rate of the power demand according to the power compensation signal flag bit. The finally output power demand is equal to the change rate of the compensated power demand multiplied by the operation cycle and continuously accumulated.

[0037] The vehicle speed judgment status flag bit, the static transmission output power judgment status flag bit, and the static transmission output torque judgment status flag bit are set to 1 when set, and 0 when cleared.

[0038] For the vehicle speed judgment flag bit, if the actual vehicle speed is less than the requested vehicle speed minus the maximum allowable deviation of the requested vehicle speed before the power integrator is activated, the static transmission output power is positive power and the static transmission output power is greater than the difference between the feedforward power demand and the allowable power increase, then the vehicle speed judgment status flag bit is 1. If any one of them is not satisfied, the vehicle speed judgment flag bit is set to 0.

[0039] For the static transmission output power judgment status flag bit, if the requested engine speed has not reached the expected engine speed corresponding to the maximum increase power of the static transmission integrator, the status value of the power demand integrator is 0 (i.e., the power demand has not changed), the static transmission output power is positive power, and at the same time the static transmission output power is greater than the engine power demand plus the hysteresis power for increasing the engine power, then the static transmission output power judgment status flag bit is set to 1. Specifically, when the above conditions are all met, the flag bit is set to 1 after a delay of T1 seconds through the delay time; otherwise, if any one of them is not satisfied, the static transmission output power judgment flag bit is set to 0.

[0040] For the static transmission output torque judgment status flag bit, if the vehicle acceleration is less than the vehicle acceleration corresponding to the maximum increase torque of the static transmission integrator, the requested engine speed is less than the expected engine speed corresponding to the maximum increase torque of the static transmission integrator, the static transmission output torque exceeds the limit torque, the actual vehicle speed is less than the requested vehicle speed minus the speed difference threshold and there is no gear change at the same time, then the static transmission output torque judgment flag bit is set to 1; otherwise, the static transmission output torque judgment flag bit is set to 0.

[0041] Specifically, no gear change means no gear change from the first gear to the second gear or from the second gear to the first gear.

[0042] Flag bit for reducing logic control of power demand integrator: If the engine power demand is greater than the feedforward power demand, the static transmission output power is less than the difference between the engine power and the allowed power increase, the actual vehicle speed is greater than the requested vehicle speed minus the maximum allowed deviation, and at the same time the engine is not in the thrust state, the flag bit of the power demand integrator is set to 1; otherwise, the flag bit is set to 0. If the flag bit for reducing logic control of the power demand integrator is set to 1, the output status value of the integrator is -1; otherwise, the output status value of the integrator is 0.

[0043] The sign of the output status value of the power demand integrator in different operating modes determines whether the integrator power demand increases, i.e., the status value is greater than 0, or the integrator power demand remains unchanged, i.e., the status value is equal to 0, or the integrator power demand decreases, i.e., the status value is less than 0.

[0044] The operating modes include three modes: automatic mode, forced downshift mode, and PTO mode.

[0045] In the automatic mode, if the vehicle speed judgment flag bit is set to 1, then after a delay of T2 seconds, the control status value of the output integrator is 1; if the static transmission output power judgment flag bit or the static transmission output torque judgment flag bit is set to 1, the control status value of the output integrator is 1; if the vehicle speed judgment flag bit, the static transmission output power judgment flag bit, and the static transmission output torque judgment flag bit are all set to 0 at the same time, the control status value of the output integrator is 0.

[0046] If a forced downshift mode signal is detected, it switches to the forced downshift mode. If the forced downshift mode signal flag bit is set to 1, the status value of the output integrator is 2; otherwise, the status value of the output integrator is 0. If the driver wants to stop, i.e., the requested vehicle speed is 0, it switches from the forced downshift mode to the automatic mode, and the status value of the output integrator is 0.

[0047] If it is detected that the PTO mode activation signal flag bit is 1, it switches from the automatic mode or the forced downshift mode to the PTO mode, then the power demand integrator fails, and the status value of the output integrator is -1. If it is detected that the PTO activation signal flag bit is 0, it switches back to the automatic mode again, and the status value of the output integrator is 0.

[0048] The rate of change of the integrated power demand is calculated by outputting the state value of the integrator. When the state value of the integrator is -1, the rate of change of the power demand is dp1; when the state value of the integrator is 0, the rate of change of the power demand is dp2; when the state value of the integrator is 1 or 2, the rate of change of the power demand is dp3. The rate of change is a function of the output torque of the static gearbox, as shown in Table 3. If it is detected that the power compensation signal flag bit is set to 1 and the state value of the integrator is greater than or equal to 0, then the power demand change rate compensation value is added to the output power demand change rate; otherwise, it is not added. The finally output power demand is equal to the rate of change of the power demand multiplied by the operating cycle and continuously accumulated and summed. The upper and lower threshold limits are applied to the finally output power demand. The lower threshold is 0, and the upper threshold is the maximum power demand of the engine minus the feedforward power demand. The feedforward power is the sum of the power demand for the vehicle to travel at a constant speed and the power demand for the vehicle to accelerate.

[0049] Power compensation control: The power demand change rate compensation value is obtained by subtracting the power demand for the vehicle to accelerate in the next cycle from the power demand for the vehicle to accelerate. If the output power of the static gearbox plus the power compensation value for the vehicle to accelerate is greater than the feedforward part of the power demand and the power demand change rate compensation value is less than 0, the power compensation signal flag bit is set to 1.

[0050] Embodiment:

[0051] As Figure 1 shown, a system for realizing the power demand of a tractor with a changing traction load includes an increasing control module for the power demand integrator, a decreasing control module for the power demand integrator, a state control module for the power demand integrator in different working modes, an integration control module for the power demand integrator, and a power compensation control module;

[0052] The increasing control module for the power demand integrator includes vehicle speed judgment, static gearbox output power judgment, and static gearbox output torque judgment. The outputs of the above three control modules are three state flag bits. The flag bit is set to 1 if it is set, and the flag bit is cleared to 0 if it is cleared.

[0053] When the vehicle speed judgment flag bit is set to 1, the following conditions need to be satisfied simultaneously: The actual vehicle speed is less than the requested vehicle speed minus the maximum allowable deviation of the requested vehicle speed before the power integrator is activated. This deviation is a function of the vehicle speed, as shown in Table 1: When the actual vehicle speed of the vehicle is 0 - 30 km / h, the maximum allowable deviation is 1; when the actual vehicle speed of the vehicle is 30 - 50 km / h, the maximum allowable deviation is 2; the static gearbox output power is greater than 10 kw, and the static gearbox output power is greater than the feedforward power demand minus the allowable power increase difference of 5 kw, then the vehicle speed judgment flag bit is set to 1; otherwise, the vehicle speed judgment flag bit is set to 0.

[0054] Table 1

[0055]

[0056] When the static transmission output power judgment flag bit is set to 1, the following conditions need to be met simultaneously: the requested engine speed has not reached the desired engine speed of 1500 rpm corresponding to the maximum increased power of the static transmission integrator, the status value of the power demand integrator is 0, that is, the power demand has not changed, the static transmission output power is positive power greater than 10 kw, and the static transmission output power is greater than the engine power demand plus the hysteresis power of 20 kw for increasing the engine power. When the above conditions are met simultaneously, the flag bit is set to 1 after a delay of 2 seconds. Conversely, the static transmission output power judgment flag bit is set to 0.

[0057] When the static transmission output torque judgment flag bit is set to 1, the following conditions need to be met simultaneously: the vehicle acceleration is less than the vehicle acceleration of 0.2 m / s^2 corresponding to the maximum increased torque of the static transmission integrator, the requested engine speed is less than the desired engine speed of 1400 rpm corresponding to the maximum increased torque of the static transmission integrator, the static transmission output torque exceeds the limit torque, which is a function of the vehicle speed, as shown in Table 2; the actual vehicle speed is less than the requested vehicle speed minus the speed difference threshold of 0.1, and there is no gear change from first gear to second gear or from second gear to first gear, then the static transmission output torque judgment flag bit is set to 1. Conversely, the static transmission output torque judgment flag bit is set to 0.

[0058] Table 2

[0059] X (km / h) 2 10 Y (Nm) 2000 800

[0060] The reduction control module of the power demand integrator: it is 1 when the flag bit is set and 0 when the flag bit is cleared. When the flag bit is set to 1, the following conditions need to be met simultaneously: the engine power demand is greater than the feedforward power demand, the static transmission output power is less than the difference between the engine power and the allowable power increase of 5 kw, the actual vehicle speed is greater than the requested vehicle speed minus the maximum allowable deviation of 1 km / h, and the engine is not in the thrust state. Conversely, the flag bit is set to 0.

[0061] The state control module of the power demand integrator in different working modes, the sign of the output state value determines whether the integrator power demand increases, that is, the state value is greater than 0, or the integrator power demand does not change, that is, the state value is equal to 0, or the integrator power demand decreases, that is, the state value is less than 0.

[0062] The working modes include: automatic mode, forced downshift mode, PTO mode.

[0063] In the automatic mode, if the vehicle speed judgment flag bit is set to 1, then after a 0.5-second delay, the status value of the output integrator is 1; if the static transmission output power judgment flag bit or the static transmission output torque judgment flag bit is set to 1, then the status value of the output integrator is 1; if the vehicle speed judgment flag bit, the static transmission output power judgment flag bit, and the static transmission output torque judgment flag bit are all set to 0 at the same time, then the status value of the output integrator is 0; if the flag bit of the reduction logic control of the power demand integrator is set to 1, then the status value of the output integrator is -1, otherwise the status value of the output integrator is 0.

[0064] If a forced downshift signal is detected, then switch from the normal mode to the forced downshift mode. If the forced downshift signal flag bit is set to 1, then the status value of the output integrator is 2, otherwise the status value of the output integrator is 0; if the driver wants to stop, that is, the requested vehicle speed is 0, then switch from the forced downshift mode to the normal mode, and the status value of the output integrator is 0.

[0065] If the PTO activation signal flag bit is detected to be 1, then switch from the normal mode or the forced downshift mode to the PTO mode, then the power demand integrator fails, and the status value of the output integrator is -1; if the PTO activation signal flag bit is detected to be 0, then switch back to the normal mode again, and the status value of the output integrator is 0.

[0066] The integration control module of the power demand integrator calculates the change rate of the integrated power demand through the status value of the output integrator. When the status value of the output integrator is -1, the change rate of the power demand is -30 kw / s; when the status value of the output integrator is 0, the change rate of the power demand is 0; when the status value of the output integrator is 1 or 2, the change rate of the power demand is dp3; this change rate is a function of the static transmission output torque, as shown in Table 3:

[0067] Table 3

[0068] X (Nm) 300 400 1000 Y (kw / s) 15 20 40

[0069] If it is detected that the power compensation signal flag bit is set to 1 and the status value of the output integrator is greater than or equal to 0, then add the power demand change rate compensation value to the output power demand change rate, otherwise do not add; the finally output power demand is equal to the change rate of the power demand multiplied by the operation cycle and continuously accumulated and summed; each operation cycle is 0.01 seconds. Limit the upper and lower threshold values of the finally output power demand, the lower threshold value is 0, and the upper threshold value is the engine maximum power demand minus the feedforward power demand.

[0070] Power compensation control module, the power demand change rate compensation value is obtained by subtracting the power demand of the vehicle accelerating in the next cycle from the power demand of the vehicle accelerating. If the static transmission output power plus the power compensation value of the vehicle accelerating is greater than the feedforward part of the power demand, where the power compensation value of the vehicle accelerating is 30 kw and the power demand change rate compensation value is less than 0, the power compensation signal flag bit is set to 1.

Claims

1. A method for realizing the power demand of a tractor's traction load change, characterized in that, It includes the following steps: S1. Obtain the increased control state value of the power demand integrator based on the vehicle speed judgment status flag, the static transmission output power judgment status flag, and the static transmission output torque judgment status flag; If the actual vehicle speed is less than the requested vehicle speed minus the maximum allowable deviation of the requested vehicle speed before the activation of the power integrator, the static transmission output power is positive power and the static transmission output power is greater than the difference between the feed-forward power demand and the allowable power increase, the vehicle speed judgment status flag is 1. If one of them is not satisfied, the vehicle speed judgment flag is set to 0; If the requested engine speed has not reached the expected engine speed corresponding to the maximum increased power of the static transmission integrator, the status value of the power demand integrator is 0, the static transmission output power is positive power, and at the same time the static transmission output power is greater than the engine power demand plus the hysteresis power for increasing the engine power, the static transmission output power judgment status flag is set to 1; otherwise, the static transmission output power judgment flag is set to 0; If the vehicle acceleration is less than the vehicle acceleration corresponding to the maximum increased torque of the static transmission integrator, the requested engine speed is less than the expected engine speed corresponding to the maximum increased torque of the static transmission integrator, the static transmission output torque exceeds the limit torque, the actual vehicle speed is less than the requested vehicle speed minus the speed difference threshold and there is no gear change, the static transmission output torque judgment flag is set to 1; otherwise, the static transmission output torque judgment flag is set to 0; S2. Obtain the status value of the integrator under the flag status of the power demand integrator reduction logic control; S3. Calculate the control state value under different working modes according to the status of the vehicle speed judgment status flag; S4. Calculate the change rate of the integral power demand based on the sum of the increased control state value of the demand integrator, the status value of the integrator under the flag status of the reduction logic control, and the control state value under different working modes. Compensate the change rate of the power demand according to the power compensation signal flag. The finally output power demand is equal to the compensated change rate of the power demand multiplied by the operation cycle and continuously accumulated and summed.

2. The method for realizing the power demand of a tractor's traction load change according to claim 1, characterized in that, The vehicle speed judgment status flag, the static transmission output power judgment status flag, and the static transmission output torque judgment status flag are 1 when set and 0 when cleared.

3. The method for realizing the power demand of a tractor's traction load change according to claim 1, characterized in that, When the requested engine speed has not reached the expected engine speed corresponding to the maximum increased power of the static transmission integrator, the status value of the power demand integrator is 0, the static transmission output power is positive power, and at the same time the static transmission output power is greater than the engine power demand plus the hysteresis power for increasing the engine power, the flag is set to 1 after a delay of T1 seconds through the delay time.

4. The method for realizing the power demand of a tractor's traction load change according to claim 1, characterized in that, If the engine power demand is greater than the feed-forward power demand, the static transmission output power is less than the difference between the engine power and the allowable power increase, the actual vehicle speed is greater than the requested vehicle speed minus the maximum allowable deviation, and at the same time the engine is not in the thrust state, the flag of the power demand integrator is set to 1, and the output status value of the integrator is -1; otherwise, the output status value of the integrator is 0.

5. The method for realizing the power demand of a tractor's traction load change according to claim 1, characterized in that, The working modes include the automatic mode, the forced downshift mode, and the PTO mode; In the automatic mode, if the vehicle speed judgment flag bit is set to 1, the control state value of the output integrator is 1; if the static transmission output power judgment flag bit or the static transmission output torque judgment flag bit is set to 1, the control state value of the output integrator is 1; if the vehicle speed judgment flag bit, the static transmission output power judgment flag bit, and the static transmission output torque judgment flag bit are simultaneously set to 0, the control state value of the output integrator is 0; If a forced downshift mode signal is detected, switch to the forced downshift mode. If the forced downshift mode signal flag bit is set to 1, the state value of the output integrator is 2, otherwise the state value of the output integrator is 0; if the requested vehicle speed is 0, switch from the forced downshift mode to the automatic mode, and the state value of the output integrator is 0; If the PTO mode activation signal flag bit is detected as 1, switch from the automatic mode or the forced downshift mode to the PTO mode, then the power demand integrator fails, and the state value of the output integrator is -1; if the PTO activation signal flag bit is detected as 0, switch back to the automatic mode again, and the state value of the output integrator is 0.

6. The method for realizing the power demand of a tractor's traction load change according to claim 1, characterized in that, When the state value of the integrator is -1, the change rate of the power demand is dp1; when the state value of the integrator is 0, the change rate of the power demand is dp2; when the state value of the integrator is 1 or 2, the change rate of the power demand is dp3.

7. A system for realizing the power demand of a tractor's traction load change, characterized in that, It includes an increase control module of the power demand integrator, a decrease control module of the power demand integrator, a state control module of the power demand integrator in different working modes, an integration control module of the power demand integrator, and a power compensation control module; The increase control module of the power demand integrator obtains the increase control state value of the power demand integrator according to the vehicle speed judgment status flag bit, the static transmission output power judgment status flag bit, and the static transmission output torque judgment status flag bit; If the actual vehicle speed is less than the requested vehicle speed minus the maximum allowable deviation of the requested vehicle speed before the power integrator is activated, the static transmission output power is positive power and the static transmission output power is greater than the difference between the feedforward power demand and the allowable power increase, then the vehicle speed judgment status flag bit is 1. If any one of them is not satisfied, the vehicle speed judgment flag bit is set to 0; If the requested engine speed does not reach the expected engine speed corresponding to the maximum increase power of the static transmission integrator, the state value of the power demand integrator is 0, the static transmission output power is positive power, and at the same time the static transmission output power is greater than the engine power demand plus the hysteresis power for increasing the engine power, then the static transmission output power judgment status flag bit is set to 1; otherwise the static transmission output power judgment flag bit is set to 0; If the vehicle acceleration is less than the vehicle acceleration corresponding to the maximum increase torque of the static transmission integrator, the requested engine speed is less than the expected engine speed corresponding to the maximum increase torque of the static transmission integrator, the static transmission output torque exceeds the limit torque, the actual vehicle speed is less than the requested vehicle speed minus the speed difference threshold and there is no gear change, then the static transmission output torque judgment flag bit is set to 1; otherwise the static transmission output torque judgment flag bit is set to 0; The reduction control module of the power demand integrator obtains the status value of the integrator under the flag bit status of the power demand integrator reduction logic control; The status control module of the power demand integrator under different working modes calculates the control status value under different working modes according to the vehicle speed to judge the status of the status flag bit; The integration control module of the power demand integrator calculates the change rate of the integrated power demand according to the sum of the increase control status value of the demand integrator, the status value of the integrator under the flag bit status of the reduction logic control, and the control status value under different working modes; The power compensation control module compensates the change rate of the power demand according to the power compensation signal flag bit, and the finally output power demand is equal to the change rate of the compensated power demand multiplied by the operation period and continuously accumulated.

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