Method for suppressing disturbance divergence in flight speed control of an aero-piston supercharged engine

Abstract

The application provides a disturbance divergence suppression method for flight speed control of an aviation piston supercharged engine, which comprises the following steps: step 1, designing speed and throttle control law; step 2, designing speed time series tracking differential; step 3, designing throttle differential dead zone device; step 4, designing time series tracking differential device control quantity; step 5, combining the time series tracking differential device control quantity with the control law; step 6, speed automatic control under the condition of no disturbance of the speed; step 7, speed divergence suppression under the condition of speed jump disturbance; and step 8, speed divergence suppression under the condition of speed jump disturbance. The engine speed is taken as the main observation quantity, the throttle change amount is combined, the time series tracking differential device is designed, the influence of noise and outliers is avoided, the speed jump is accurately captured, the feedforward negative compensation control quantity is designed according to the jump quantity, the positive and negative feedback phenomenon of the speed-speed is predicted and suppressed in advance, and the flight safety of the aircraft can be ensured.

Description

Technical Field

[0001] This invention relates to the field of aero-engine technology, and more specifically to a method for suppressing disturbance divergence in the flight speed control of an aero-engine piston turbocharger. Background Technology

[0002] Flight speed is a crucial aircraft motion parameter, determining its motion state and influencing important indicators such as flight time and service ceiling, thus impacting its economic performance. Furthermore, maintaining and controlling flight speed is coupled with maintaining and controlling altitude, serving as a necessary prerequisite for flight path control. To reduce the demands on and dependence on flight operators, most aircraft employ flight speed control systems. The automatic throttle control system is the most commonly used speed control method for cruise flight. It primarily adjusts the throttle opening based on speed deviation, regulating the total amount of air-fuel mixture entering the engine combustion cylinder, thereby determining the engine's output power and speed, and ultimately altering engine thrust to control flight speed. A block diagram of the speed-throttle automatic control system is shown below. Figure 1 As shown:

[0003] Flight speed serves as the setpoint for the automatic controller, while observed flight speed measurements provide feedback. Error information drives the controller to generate throttle control inputs, which in turn control the engine speed, altering thrust to achieve closed-loop flight speed control. Vertical altitude and pitch angle control are somewhat interrelated with speed control, handled by the corresponding autopilot systems; these details are omitted here. The relationships are as follows:

[0004] e = V g -V;

[0005] δ T =f(e);

[0006] δ e = g(H,θ);

[0007] Among them, V g Given a velocity, V is the velocity, e is the velocity error, and δ T For throttle body setting, δ e The elevator is given by H, where H is the altitude and θ is the pitch angle.

[0008] Piston-type aero engines are the mainstream power source for low- and medium-altitude, long-endurance unmanned aerial vehicles (UAVs), with propellers being the primary propulsion system. Two-stroke aero piston engines are characterized by high power-to-weight ratio, simple structure, low cost, and easy maintenance, and occupy an important position in the field of small and medium-sized UAV power. As altitude increases, atmospheric pressure, air density, and oxygen content all decrease. Naturally aspirated two-stroke aero piston engines experience a significant drop in output power and torque, an increase in fuel consumption, and a rapid deterioration in engine performance, failing to meet the power requirements of the aircraft and limiting its practical service ceiling.

[0009] Supercharging technology is a crucial and effective means of enhancing and restoring engine power, and it can be used for high-altitude power recovery in two-stroke engines. Exhaust gas turbocharging technology utilizes turbocharging to achieve high-altitude power recovery, employing techniques such as direct injection, exhaust bypass valve control, and exhaust tuning to increase intake pressure using the engine's own exhaust energy, thereby increasing the intake volume per cycle and improving engine performance. However, the engineering implementation of supercharging matching for two-stroke aero engines is not yet mature, affecting flight speed control.

[0010] The engine's exhaust power and turbocharger power demand increase exponentially with engine speed at certain stages, thus engine speed and boost pressure exhibit a positive correlation. Therefore, at certain stages of rapid engine speed increase, the turbocharger will directly switch from an inactive state to a boosted state, resulting in a jump in engine power and engine speed; conversely, at certain stages of engine speed decrease, the turbocharger will also directly switch from an active state to an inactive state, resulting in a jump in power and engine speed (e.g., ...). Figure 2 (As shown).

[0011] During flight, aircraft are affected by factors such as changes in flight path, atmospheric turbulence, gusts, and wind shear. These factors cause drastic changes in the direction and speed of airflow over the propeller, resulting in fluctuations in propeller speed. When these speed fluctuations occur near the engine's boost speed jump point, the supercharger's operating condition is severely affected.

[0012] When the airflow to the propeller suddenly increases (such as a sudden gust of wind against the direction of flight), the propeller drag decreases and its speed increases. The turbocharger then enters its working state from a non-operating state, causing a jump in engine speed, power, and torque, resulting in an increase in engine thrust. This increase in thrust further increases the aircraft's speed, exacerbating the increase in propeller airflow and speed, thus creating a positive feedback loop.

[0013] Conversely, when the airflow to the propeller suddenly decreases (such as a sudden gust of wind in the direction of the aircraft's flight), the propeller drag increases and the speed decreases. The supercharger, which was originally in operation, will disengage, causing a sharp drop in engine speed, power, and torque, resulting in a decrease in engine thrust. The decrease in thrust exacerbates the decrease in engine speed, forming a positive feedback loop.

[0014] In both scenarios, the positive feedback loop drastically alters the aircraft's speed. During cruise flight, the autopilot typically follows a given altitude and trajectory; altitude control often exacerbates these speed changes, causing the aircraft to deviate from its intended operating state. Especially when speed decreases sharply, conventional control can cause the aircraft to stall, jeopardizing flight safety.

[0015] In conclusion, it is necessary to further innovate existing technologies. Summary of the Invention

[0016] To address the technical problems existing in the background art, this invention proposes a disturbance divergence suppression method for flight speed control of aero-piston turbocharged engines. Its concept is reasonable and can ensure the flight safety of such aircraft. It has the important advantages of identifying engine speed jumps and providing feedforward compensation before speed control divergence to ensure flight speed safety.

[0017] To solve the above-mentioned technical problems, the present invention provides a method for suppressing disturbance divergence in the flight speed control of an aero-piston turbocharged engine, which includes the following steps:

[0018] Step 1: Design the speed and throttle control law; the specific process is as follows:

[0019] Based on the aircraft's cruise operating point, and neglecting the influence of the engine's lift operating point, the speed and throttle control laws are designed as follows:

[0020]

[0021] δ Ttrim =A(V) g );

[0022] Where, δ T Given the throttle damper, e(t) is the speed error, and K... p K is the proportional control coefficient. i K is the integral coefficient. d δ is the differential coefficient; Ttrim Given a velocity V g The corresponding damper balance is given, and A is the balance correspondence symbol;

[0023] Step 2: Design the rotational speed time series tracking derivative; the specific process is as follows:

[0024] Design a time series tracking differentiator, set the number of sequences w according to the engine communication frequency, obtain the speed jump threshold Δ from ground tests, set the number of jump judgments k, and perform calculation, judgment and sequence update in each communication cycle:

[0025]

[0026] Where n is the rotational speed; i = 1 to w / 2;

[0027] When the time series tracks the absolute value of each differential component |Δ(i)|>Δ Th When the number of signals exceeds k, the tracking differentiator captures the jump signal;

[0028] Step 3: Design the throttle differential dead zone device;

[0029] Step 4: Design the control quantity for the time series tracking differentiator;

[0030] Step 5: Combine the time series tracking differential control quantity with the control law;

[0031] Step 6: Automatic speed control under undisturbed rotation speed;

[0032] Step 7: Suppressing velocity divergence under speed jump disturbance;

[0033] Step 8: Suppressing velocity divergence under speed drop disturbance.

[0034] The disturbance divergence suppression method for flight speed control of the aforementioned aero-piston turbocharged engine, wherein: step 3 specifically involves adding a dead zone to the differential of the throttle input: if dδ T If / dt is greater than or less than the design threshold for multiple consecutive cycles, the throttle differential dead zone will output 1; otherwise, it will output 0.

[0035] The disturbance divergence suppression method for flight speed control of the aforementioned aero-piston turbocharged engine, wherein step 4 specifically involves: for conditions satisfying |Δ(i)|>Δ Th Δ(i) is calculated using the average value adv(Δ). If adv(Δ) > Δ max Then the time series tracking differential limiting output Δ max Otherwise, output adv(Δ); multiply this by the result of step 3, and then multiply by the negative gain control parameter -K. n The output quickly adjusts the throttle position, determines the engine intake air volume, affects the available exhaust power, suppresses turbocharger jumps and returns to the original state, and controls the aircraft in advance before acceleration accumulates.

[0036] The disturbance divergence suppression method for flight speed control of the aforementioned aviation piston turbocharged engine includes step 5, which specifically involves summing the speed-throttle control law calculation output, trim setpoint, and time series tracking differentiator control quantity from step 1 to form a throttle control quantity output to the engine, thereby achieving flight speed control under disturbance-free, speed jump, and speed drop conditions.

[0037] The disturbance divergence suppression method for flight speed control of the aforementioned aviation piston turbocharged engine, wherein step 6 is specifically as follows: when atmospheric conditions are relatively stable, the engine speed is free from external disturbances and the speed is stable, the speed error is eliminated by the speed-throttle control law in step 1, and outliers are identified and eliminated by the time series tracking differentiator in step 2 above, thereby achieving automatic speed control without steady-state error through the speed-throttle control law in step 1.

[0038] The disturbance divergence suppression method for flight speed control of the aforementioned aviation piston supercharged engine, wherein the specific process of step 7 is as follows: When atmospheric conditions are poor and disturbance factors are present, a sudden increase in airflow causes the propeller speed to rise. If the supercharger does not change abruptly, the speed increases and the absolute value of the error increases. The error is eliminated by the speed-throttle control law in step 1, achieving automatic speed control without static error. If the supercharger changes abruptly and the speed jumps, the speed increases and the absolute value of the error increases. The speed jump is identified by the time series tracking differentiator in step 2. The feedforward control quantity is calculated by the speed time series tracking differentiator, the throttle differential dead zone device, and the time series tracking differentiator in steps 2 to 4, and superimposed with the speed-throttle control law in step 1 to complete speed divergence suppression.

[0039] The disturbance divergence suppression method for flight speed control of the aforementioned aviation piston supercharged engine, wherein the specific process of step 8 is as follows: When the airflow suddenly decreases, causing the propeller speed to decrease, if the supercharger does not change abruptly, the speed increases and the absolute value of the error increases. The error is eliminated by the speed-throttle control law in step 1, achieving automatic speed control without static error; if the supercharger changes abruptly and the speed drops sharply, the speed decreases and the absolute value of the error increases. The speed drop is identified by the time series tracking differentiator in step 2. The feedforward control quantity is calculated by the speed time series tracking differentiator, the throttle differential dead zone device, and the time series tracking differentiator in steps 2 to 4, and superimposed with the speed-throttle control law in step 1 to complete the speed divergence suppression.

[0040] By adopting the above technical solution, the present invention has the following beneficial effects:

[0041] Excessive coefficients in conventional airspeed closed-loop control can reduce the lifespan of turbocharged piston engines and potentially cause self-excited oscillations and divergence at speed jump points; conversely, excessively small coefficients are insufficient to suppress positive airspeed feedback caused by speed jumps. This invention utilizes a time-series tracking differential to identify engine speed jumps. By combining the control quantity of the time-series tracking differential with the control law, it provides feedforward compensation for adverse airspeed factors caused by speed jumps, enabling automatic speed control in scenarios with no disturbance, speed jump disturbances, and speed jump descent disturbances. This improves aircraft platform stability and solves the problem of airspeed closed-loop control divergence caused by speed jump characteristics. Attached Figure Description

[0042] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0043] Figure 1Block diagram of the automatic control system for speed-throttle damper;

[0044] Figure 2 A graph showing the relationship between the energy available from the exhaust of a certain engine, the energy required by the turbine, and the engine speed.

[0045] Figure 3 This is a block diagram of the speed feedforward control of the measurement time series tracking differentiator involved in the disturbance divergence suppression method for flight speed control of the aero-piston turbocharged engine of the present invention.

[0046] Figure 4 This is a diagram showing the correspondence between time-series tracking differentiator rotation speed observation signals involved in the disturbance divergence suppression method for flight speed control of aero-piston turbocharged engines in this invention.

[0047] Figure 5 This is a schematic diagram of the throttle differential dead zone device involved in the disturbance divergence suppression method for flight speed control of an aero-piston turbocharged engine of the present invention.

[0048] Figure 6 This is a schematic diagram of the time-series tracking differentiator control quantity involved in the disturbance divergence suppression method for flight speed control of an aero-piston turbocharged engine of the present invention.

[0049] Figure 7 This is a schematic diagram of the disturbance divergence suppression controller for flight speed control involved in the disturbance divergence suppression method for flight speed control of the aero-piston turbocharged engine of the present invention.

[0050] Figure 8 This is a block diagram illustrating the principle of speed divergence suppression under speed jump disturbance in the disturbance divergence suppression method for flight speed control of aero-piston turbocharged engines of the present invention.

[0051] Figure 9 Block diagram of the principle for suppressing velocity divergence under speed drop disturbance. Detailed Implementation

[0052] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] The present invention will be further explained below with reference to specific embodiments.

[0054] This embodiment provides a disturbance divergence suppression method for flight speed control of an aero-piston turbocharged engine. It uses engine speed as the main observation, and in conjunction with the throttle valve change, designs a time series tracking differentiator to avoid the influence of noise and outliers, accurately capture speed jumps, and design a feedforward negative compensation control quantity based on this jump variable to predict and suppress the positive feedback phenomenon of speed-speed.

[0055] like Figure 3 As shown, the process of velocity feedforward control for the time-series tracking differentiator is as follows:

[0056] Flight speed is used as the controller's input, and flight speed observations serve as feedback. Error information drives the controller to generate throttle control inputs. Engine speed, as a time-series tracking differentiator observation, provides feedforward compensation, jointly driving the throttle to control engine speed and change thrust to achieve closed-loop flight speed control. Longitudinal altitude and pitch angle control are somewhat interrelated with speed control and are handled by the corresponding autopilots, which will not be elaborated here. The boost control system is controlled by the engine, which will also not be elaborated here. The relationships are as follows:

[0057] e = V g -V;

[0058] δ T =f(e)+F(n,δ) T );

[0059] δ e = g(H,θ);

[0060] n = G(δ) T ,p);

[0061] Among them, V g Given a velocity, V is the velocity, e is the velocity error, and δ T For throttle body setting, δ e For the elevator settings, H is altitude, θ is pitch angle, p is boost, and n is rotational speed.

[0062] The present invention provides a method for suppressing disturbance divergence in flight speed control of an aero-piston turbocharged engine, which specifically includes the following steps:

[0063] (1) Design speed-throttle damper control law

[0064] Based on the aircraft's cruise operating point, neglecting the influence of the engine's lift operating point, design the speed-throttle control law:

[0065]

[0066] δ Ttrim =A(V) g );

[0067] Where, δT Given the throttle damper, e(t) is the speed error, and K... p K is the proportional control coefficient. i K is the integral coefficient. d δ is the differential coefficient; Ttrim Given a velocity V g The corresponding damper balance is given, and A is the balance correspondence symbol.

[0068] To avoid excessive sensitivity of control parameters to speed errors, which could cause frequent operation of the throttle mechanism, resulting in a sharp reduction in engine life and in-flight malfunctions.

[0069] (2) Design of rotational speed time series tracking differential

[0070] To prevent the adverse effects of noise, outliers, and other harmful signals on the engine speed signal, a time-series tracking differentiator is designed. The number of sequences w (which must be even) is set according to the engine communication frequency. The speed jump threshold Δ is obtained from ground tests, and the number of jump judgments k is set. Calculation, judgment, and sequence update are performed in each communication cycle.

[0071]

[0072] ...

[0073]

[0074] Where n is the rotational speed.

[0075] When the time series tracks the absolute value of each differential component |Δ(i)|>Δ Th When the number of signals exceeds k, the tracking differentiator captures the jump signal.

[0076] The correspondence between the speed observation signals is as follows: n(w) represents the speed observation value at the current moment, n(i) represents the speed observation value wi times ago, and n(1) represents the speed observation value wi times ago. The schematic diagram is shown below. Figure 4 As shown; where vertical lines of different colors represent rotational speed sampling, the horizontal axis represents the sampling time, n(i) is the rotational speed at time i, T1 and Ti are the start times of the 1st and 1st observation cycles, and the horizontal axis scales such as T1+1 and Ti+w / 2 represent the sampling time.

[0077] (3) Design of throttle differential dead zone

[0078] To avoid mishandling of engine speed changes caused by throttle position adjustments, a dead zone is added to the throttle input derivative:

[0079] If dδ T If / dt is greater than or less than the design threshold for multiple consecutive cycles, the throttle differential dead zone outputs 1; otherwise, it outputs 0 (e.g., ...). Figure 5 (As shown).

[0080] (4) Design the control quantity of the time series tracking differentiator (e.g.) Figure 6 (where d / dt represents differential calculation) for |Δ(i)|>Δ Th Δ(i) is calculated using the average value adv(Δ). If adv(Δ) > Δ max Then the time series tracking differential limiting output Δ max Otherwise, output adv(Δ); multiply by the result of step (3), and then multiply by the negative gain control parameter -K. n The output quickly adjusts the throttle position, determines the engine intake air volume, affects the available exhaust power, suppresses turbocharger jumps and returns to the original state, and controls the aircraft in advance before acceleration accumulates.

[0081] (5) Combining the control input and control law of the time series tracking differentiator

[0082] The output of the control law calculation in step (1), the trim setpoint, and the control quantity of the time series tracking differentiator are summed to form the throttle control quantity output to the engine, thereby achieving flight speed control under disturbance-free, speed jump, and speed drop conditions. (e.g.) Figure 7 )

[0083] (6) Automatic speed control under undisturbed rotation speed

[0084] When atmospheric conditions are relatively stable, the engine speed is not affected by external disturbances and the speed is stable. The speed error will be eliminated by the control law in step 1, and the outlier will be identified and eliminated by the time series tracking differentiator in step (2) above. Automatic speed control without static error is achieved through the speed-throttle control law in step (1) above.

[0085] (7) Suppression of velocity divergence under speed jump disturbance

[0086] When atmospheric conditions are poor, with disturbances such as turbulence, sudden winds, and wind shear, the sudden increase in airflow causes the propeller speed to rise. If the turbocharger does not change abruptly, the speed increases and the absolute value of the error increases. The error is eliminated by the control law in step (1), achieving automatic speed control without static error. If the turbocharger changes abruptly, the speed jumps, the speed increases, and the absolute value of the error increases, the speed jump is identified by the time series tracking differentiator in step (2). The feedforward control quantity is calculated by the speed time series tracking differentiator, throttle differential dead zone device, and time series tracking differentiator in steps (2) to (4), and superimposed with the speed-throttle control law in step (1) to complete speed divergence suppression (e.g., Figure 8 ).

[0087] (8) Suppression of velocity divergence under speed drop disturbance

[0088] When the airflow suddenly decreases (tailwind), causing the propeller speed to drop, if the turbocharger does not change abruptly, the speed increases and the absolute value of the error increases. The error is eliminated by the control law in step (1), achieving automatic speed control without static error. If the turbocharger changes abruptly and the speed drops sharply, the speed decreases and the absolute value of the error increases. The speed drop is identified by the time-series tracking differentiator in step (2). The feedforward control quantity is calculated by the speed time-series tracking differentiator, throttle differential dead zone device, and time-series tracking differentiator in steps (2) to (4), and superimposed with the speed-throttle control law in step (1) to complete speed divergence suppression (e.g., Figure 9 ).

[0089] This invention is well-conceived and can ensure the flight safety of such aircraft. It has important advantages such as recognizing sudden changes in engine speed and providing feedforward compensation before speed control divergence to ensure flight speed safety.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for suppressing disturbance divergence in flight speed control of an aircraft piston turbocharged engine, characterized in that... This includes the following steps: Step 1: Design the speed and throttle control law; the specific process is as follows: Based on the aircraft's cruise operating point, and neglecting the influence of the engine's lift operating point, the speed and throttle control laws are designed as follows: ； ； Where, δ T Given the throttle damper, e(t) is the speed error, and K... p K is the proportional control coefficient. i K is the integral coefficient. d δ is the differential coefficient; Ttrim Given a velocity V g The corresponding damper balance is given, and A is the balance correspondence symbol; Step 2: Design the rotational speed time series tracking derivative; the specific process is as follows: Design a time-series tracking differentiator, set the number of sequences w according to the engine communication frequency, and obtain the speed jump threshold Δ based on ground tests. Th Set the number of transition judgments k, and perform calculation, judgment, and sequence update in each communication cycle: ； ； ； ； Where n is the rotational speed; i = 1 ~ w / 2; When the time series tracks the absolute value of each differential component |Δ(i)|>Δ Th When the number of signals exceeds k, the tracking differentiator captures the jump signal; Step 3: Design the throttle differential dead zone; specifically, add dead zone processing to the given throttle differential: if dδ T If / dt is greater than or less than the design threshold for multiple consecutive cycles, the throttle differential dead zone controller outputs 1; otherwise, it outputs 0. Step 4: Design the control quantity for the time series tracking differentiator; the specific process is as follows: for the time series tracking differentiator, the control quantity is determined by |Δ(i)|>Δ. Th Δ(i) is calculated using the average value adv(Δ). If adv(Δ) > Δ max Then the time series tracking differential limiting output Δ max Otherwise, output adv(Δ); multiply this by the result of step 3, and then multiply by the negative gain control parameter -K. n The output quickly adjusts the throttle position, determines the engine intake air volume, affects the exhaust available power, suppresses turbocharger jumps and returns to the original state, and controls the aircraft in advance before acceleration accumulates. Step 5: Combine the time-series tracking differentiator control quantity with the control law; specifically, the speed-throttle control law calculation output, trim setpoint and time-series tracking differentiator control quantity calculated in Step 1 are summed to form the throttle control quantity output to the engine, so as to realize flight speed control under the conditions of no disturbance, speed jump and speed drop. Step 6: Automatic speed control under undisturbed rotation speed; Step 7: Suppressing velocity divergence under speed jump disturbance; Step 8: Suppressing velocity divergence under speed drop disturbance.

2. The disturbance divergence suppression method for flight speed control of an aero-piston turbocharged engine as described in claim 1, characterized in that, The specific process of step 6 is as follows: when the atmospheric conditions are relatively stable, the engine speed is not disturbed by external factors and the speed is stable. The speed error is eliminated by the speed-throttle control law in step 1, and the outliers are identified and eliminated by the time series tracking differentiator in step 2. Automatic speed control without static error is achieved through the speed-throttle control law in step 1.

3. The disturbance divergence suppression method for flight speed control of an aero-piston turbocharged engine as described in claim 1, characterized in that, The specific process of step 7 is as follows: When atmospheric conditions are poor and there are disturbances, the sudden increase in airflow causes the propeller speed to rise. If the turbocharger does not change abruptly, the speed increases and the absolute value of the error increases. The error is eliminated by the speed-throttle control law in step 1, realizing automatic speed control without static error. If the turbocharger changes abruptly and the speed jumps, the speed increases and the absolute value of the error increases. The speed jump is identified by the time series tracking differentiator in step 2. The feedforward control quantity is calculated by the speed time series tracking differentiator, the throttle differential dead zone device and the time series tracking differentiator in steps 2 to 4, and superimposed with the speed-throttle control law in step 1 to complete the speed divergence suppression.

4. The disturbance divergence suppression method for flight speed control of an aero-piston turbocharged engine as described in claim 1, characterized in that, The specific process of step 8 is as follows: When the airflow suddenly decreases, causing the propeller speed to decrease, if the turbocharger does not change abruptly, the speed increases and the absolute value of the error increases. The error is eliminated by the speed-throttle control law in step 1, realizing automatic speed control without static error. If the turbocharger changes abruptly and the speed drops sharply, the speed decreases and the absolute value of the error increases. The speed drop is identified by the time series tracking differentiator in step 2. The feedforward control quantity is calculated by the speed time series tracking differentiator, the throttle differential dead zone device and the time series tracking differentiator in steps 2 to 4, and superimposed with the speed-throttle control law in step 1 to complete speed divergence suppression.

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