2390results about "Fuel injection control" patented technology

The invention discloses an air-fuel ratio control method for a high-pressure direct injection engine in a diesel-natural gas dual-fuel cylinder, and relates to the technical field of engine control, and the air-fuel ratio control method comprises the following steps: collecting diesel mass flow, natural gas volume flow and natural gas component data, and determining a diesel-natural gas mixing ratio; a basic target air-fuel ratio is obtained by combining the real-time rotating speed of an engine, the load and the diesel oil-natural gas mixing proportion; based on the pressure and temperature of the intake manifold and the rotating speed of the engine, the target air-fuel ratio after model correction is obtained; the working condition load change rate is detected, the pre-optimized air-fuel ratio trajectory MAP is called, and a transient correction target value is generated; calculating the deviation between the transient correction target value and the measured value of the air-fuel ratio sensor and the deviation change rate, and outputting an air-fuel ratio correction value; and the final target air-fuel ratio is calculated and sent to an air flow control valve to execute air inlet adjustment. The method is suitable for engine application scenes requiring high-precision and self-adaptive control to improve combustion efficiency and reduce emission.

The invention discloses a dual-fuel engine combustion control method based on hydrogen-ammonia energy ratio and gas distribution overlap angle regulation and control, which comprises the following steps: 1) fuel ratio control: acquiring current operation state parameters of an engine, determining a target AER according to preset mapping, regulating ammonia gas supply quantity and hydrogen supply quantity to enable the actual AER to reach the target AER, and controlling the fuel ratio; the AER is adaptively set according to engine load and combustion stability conditions; 2) valve timing control: adjusting the opening time of an intake valve or the closing time of an exhaust valve through a variable valve timing mechanism so as to change a valve timing overlap angle VOA, wherein the VOA is set to be a negative value, a small overlap angle or a positive overlap angle according to the working condition of an engine; (3) injection time sequence optimization is conducted, specifically, the injection time of ammonia gas and the in-cylinder direct injection time of hydrogen are controlled respectively, and coordinated optimization of a fuel injection strategy and valve timing is achieved; and 4) closed-loop steady-state control: monitoring a combustion state and an emission index in real time, comparing the combustion state and the emission index with a threshold value to serve as a feedback signal, and correcting the target AER and VOA settings in time. According to the dual-fuel engine combustion control method based on regulation and control of the hydrogen-ammonia energy ratio and the gas distribution overlapping angle, the energy ratio of hydrogen fuel and ammonia fuel and the overlapping opening angle of an intake valve and an exhaust valve are dynamically adjusted under different working conditions, so that the combustion reaction rate and temperature are coordinated, and the stable and efficient combustion process is achieved; and harmful emissions of NOx, unburned ammonia and the like are obviously reduced.

The invention relates to the technical field of engine control, in particular to an engine combustion control method, device and system based on double oil sprayers and a computer program product. Comprising the steps that when an engine enters a lean-burn working condition and meets a self-learning condition, self-learning of the injection starting angle and the excess air coefficient of an auxiliary oil injector is conducted; ignition advance angle self-learning of the auxiliary fuel injector is carried out; and fuel injection control over the auxiliary fuel injector is conducted on the basis of the injection starting angle, the excess air coefficient and the ignition advance angle obtained through self-learning. And when refined fuel oil control is carried out to achieve the optimal fuel consumption of the engine, the lowest NOx emission requirement under the lean-burn working condition of the engine is met.

The invention discloses a method for actively regulating and controlling the temperature of an exhaust pipe under the sliding working condition of an engine, and relates to the engine control technology, the current working condition of the engine is recognized, and if the current working condition is the sliding working condition, an exhaust temperature increasing regulation and control mode is started; according to the exhaust temperature increasing regulation and control mode, a temperature rise demand target is calculated according to the temperature difference value between the current exhaust temperature of an exhaust pipe of the engine and the set target exhaust temperature, and a temperature rise control strategy is selected according to the temperature rise demand target and executed. The invention further discloses a system for actively regulating and controlling the temperature of the exhaust pipe under the engine sliding working condition. The exhaust temperature in the sliding process is increased, the cold and hot temperature difference of the exhaust pipe is reduced, and therefore the reliability of the exhaust pipe is improved.

In a method for adjusting a vehicle parameter, where the vehicle is equipped with an exhaust gas sensor, an exhaust gas sensor signal is received. Based on this signal, a parameter representative of the vehicle's air-fuel ratio is determined. Depending on this parameter, it is then determined whether a transition from a superstoichiometric to a substoichiometric air-fuel mixture, or from a substoichiometric to a superstoichiometric air-fuel mixture, is imminent. If a transition is imminent, the current value of the parameter is adjusted until a predefined termination condition is met. The current parameter value is then transmitted.

This invention relates to the field of automotive energy management and data-driven technology, providing a data-driven method and system for correcting engine transient fuel consumption. The method includes the following steps: real-time acquisition of multi-source data during vehicle operation; preprocessing of the multi-source data to output effective operating condition data; construction of three transient fuel consumption correction sub-models based on various artificial neural networks and the effective operating condition data; linear weighted fusion of the three transient fuel consumption correction sub-models to obtain a total transient fuel consumption correction model; and correction of engine transient fuel consumption based on the total transient fuel consumption correction model. This invention, by real-time acquisition of multi-source data during vehicle operation and establishing a total transient fuel consumption correction model through data-driven and intelligent modeling methods, achieves accurate prediction and real-time correction of transient fuel consumption, thereby improving the fuel economy and energy management optimization effect of hybrid vehicles under actual operating conditions.

The invention discloses an automobile filter abnormity monitoring method based on multi-sensor fusion, which comprises the following steps: acquiring and preprocessing multi-modal sensing data to generate standardized multi-modal sensing data; carrying out working condition identification and standardization on multi-modal sensing data to obtain working condition state variables and a monitoring sequence; an improved Holt-Winters model is constructed, and an automobile filter prediction baseline is obtained; calculating a residual error sequence and performing hierarchical processing to obtain a low-frequency residual error and a high-frequency residual error; executing a CUSUM algorithm to obtain a bidirectional CUSUM statistical magnitude; statistical analysis is carried out, a self-adaptive threshold value is constructed, and the category and severity of the abnormal event are judged. According to the method, the improved Holt-Winters model and the CUSUM algorithm are combined, so that accurate abnormal event identification and classification of the automobile filter in a complex multi-working-condition environment are realized.

The invention relates to the field of vehicle control, in particular to an intelligent oil-saving sliding control method and system for an AMT commercial vehicle and the commercial vehicle, and the method comprises the steps: obtaining a gradient threshold interval and hysteresis width corresponding to a current state based on the total load of the vehicle, the real-time vehicle speed and the real-time road gradient; whether the engine water temperature and the accelerator opening degree signal meet preset fuel-saving sliding admission conditions or not is judged in real time; when all the access conditions are met and the real-time gradient and the vehicle speed are within the threshold interval, gear combination of the AMT gearbox is maintained, an engine is controlled to enter a fuel cut-off mode, and the vehicle enters an intelligent fuel-saving sliding state based on engine reverse towing; and if the real-time gradient exceeds the safety range, engine fuel oil supply is immediately recovered, and the in-cylinder braking or exhaust braking function of the engine can be cooperatively activated, so that the fuel-saving sliding state is stably quitted. And on the premise of ensuring compliance and safety of the whole process, the fuel economy is effectively improved.

The application discloses a fuel injection control method and device, electronic equipment and storage medium. The fuel injection control method comprises the following steps: after the accelerator pedal is stepped on, determining the engine torque demand according to the current working state of the engine and the stepping amount of the accelerator pedal, and determining the required intake air amount and the required fuel amount of the engine according to the engine torque demand; determining the current throttle opening of the engine according to the required intake air amount, and after the current fuel injection pulse width of the fuel injector is determined according to the required fuel amount, controlling the throttle valve to hit the target position corresponding to the current throttle opening, and controlling the fuel injector to open to the current fuel injection pulse width; acquiring the current fuel injection rail pressure, and determining the fuel injection mass flow of the engine by querying the fuel injection mass flow calculation MAP according to the current fuel injection pulse width and the current fuel injection rail pressure; and inputting the fuel injection mass flow into the engine model to output the current air-fuel ratio. The application realizes real-time adjustment of the fuel injection mass flow.

The invention provides a control method and device for consistency of all cylinders of an engine and a vehicle. The method comprises the steps that the rotating speed and torque of the engine are obtained, and the rotating speed and torque of the engine are obtained; determining that the engine is in a low-speed and low-load working condition under the condition that the engine rotating speed is in a first preset range and the engine torque is in a second preset range; under the condition that the engine is in the low-speed and low-load working condition, the camshaft phase is controlled to be delayed relative to the crankshaft phase, so that opening of an intake valve of the engine is delayed, and the problem that in the prior art, the actual EGR rate consistency of all cylinders of the engine is poor is solved.

The invention discloses a method and system for calculating the excess air coefficient of a pure hydrogen fuel internal combustion engine, and the method comprises the steps: obtaining the oxygen concentration in the intake air of the pure hydrogen fuel internal combustion engine; and the hydrogen concentration, the oxygen concentration and the nitric oxide concentration in exhaust gas of the pure hydrogen fuel internal combustion engine are obtained. And calculating the excess air coefficient of the pure hydrogen fuel internal combustion engine by solving a material balance equation set according to the oxygen concentration in the intake air and the hydrogen concentration, the oxygen concentration and the nitric oxide concentration in the exhaust. Therefore, according to the calculation method for the excess air coefficient of the pure hydrogen fuel internal combustion engine, the calculation accuracy of the excess air coefficient is improved, and therefore the combustion efficiency and the emission control effect of the hydrogen internal combustion engine are optimized.

The invention relates to the technical field of generator fuel pump control, in particular to an energy-saving generator fuel pump optimization method and system. Comprises: continuously collecting operation parameters of a generator system, and determining whether the generator system is in a stable operation condition; after the stable operation working condition is judged, perturbation testing is executed, and the actual output pressure and the actual fuel flow of the fuel pump are obtained; calculating the performance deviation of the fuel pump, and carrying out trend analysis to identify continuous performance drift; when the trend analysis shows that continuous performance drifting exists, self-adaptive correction is conducted on the fuel pump control basis to obtain the corrected fuel pump control basis; and the corrected fuel pump control basis is applied to control operation of the fuel pump. The problems that hidden energy consumption is increased and equipment failure risks are caused when an existing generator fuel pump control system is in the face of tiny changes of fuel physical attributes and gradual degradation of the performance of a fuel pump are solved.

The invention relates to an intelligent valve terminal control method and system for electronic injection of an aero-engine, and the method comprises the steps: obtaining multi-source state data in the operation of the engine, and carrying out the preprocessing to form a high-dimensional time sequence feature vector; a deep learning inference model is utilized to accurately identify a current working condition and predict a future evolution trend; generating an optimal fuel injection strategy based on a model predictive control and reinforcement learning mixed strategy; on-line self-adaptive correction is carried out by monitoring a comparison result of an actual response and an expected output, and an optimization instruction sequence is generated; and finally, converting the signal into a multi-channel synchronous pulse width modulation driving signal, and accurately controlling the coordinated action of a plurality of fuel injection valves. Intelligent and fine control over fuel injection is achieved, the combustion efficiency, the dynamic response speed and the operation stability of the engine are effectively improved, meanwhile, emission is reduced through multi-target optimization, and the problems that in the prior art, control lags behind, multi-valve cooperation precision is insufficient, and working condition adaptability is poor are solved.

A method includes initializing an estimated fuel property associated with a fuel of an engine system. The method also includes determining an estimated quantity associated with operation of the engine based on a model. The method also includes receiving a signal indicative of a measured quantity corresponding to the estimated quantity. The method also includes determining the measured quantity based on the received signal. The method also includes determining a residual based on the estimated quantity and the measured quantity. The method also includes updating the estimated fuel property based on the residual. The method also includes controlling one or more operational parameters of the engine based on the update of the estimated fuel property.

The invention discloses a natural gas-diesel oil injection switching control system of a dual-fuel diesel engine, which relates to the technical field of automatic control and comprises a data acquisition monitoring module, a fuel analysis module, a prediction control module, a control optimization module and a switching protection module. Engine operation parameter data are collected in real time through an engine sensor interface and preprocessed, and fuel dynamic proportion analysis is carried out according to different rotating speeds and load intervals of an engine by taking a preset proportion as an initial reference datum and applying an intelligent algorithm; the engine can obtain the most appropriate natural gas and diesel oil mixing proportion under various working conditions, according to an ideal gas state equation, based on pressure and temperature data, monitored in real time, in a gas supply pipeline, dynamic compensation is conducted on the gas volume flow, real-time gas supply energy is calculated, the gas supply amount can be accurately controlled in the mode, and the gas supply efficiency is improved. It is guaranteed that the engine obtains stable and accurate energy supply, and therefore stable operation of the engine is maintained.

The invention relates to a cooperative control method and system for lean-burn emission of a marine low-zero carbon fuel engine. The method comprises the steps that real-time in-cylinder pressure and temperature data are collected, and an in-cylinder pressure curve and an in-cylinder temperature curve are obtained through time sequence alignment, filtering denoising and interpolation fitting processing; extracting time sequence data based on the curve, calculating average effective pressure and peak temperature in a cylinder to determine a current load interval, and marking a risk tag sequence; calculating the generation rate of the nitrogen oxides and the particulate matters by matching with reaction condition parameters, and extracting reverse variation characteristics to obtain strong mutual exclusion correlation of the nitrogen oxides and the particulate matters; and based on the associated starting model, predicting and controlling the output oil injection quantity and the air inflow adjusting quantity, calculating the transient time sequence lag quantity through a dynamic lag model, and after superposition, calibrating through a combustion phase matching algorithm to generate an oil injection timing and air inlet valve opening control instruction after transient adjustment. The method is adaptive to the combustion characteristics of low-zero-carbon fuel, emission contradictions are accurately captured, transient emission peak values are avoided, and multi-pollutant collaborative control is achieved.

The present application relates to the technical field of engine, and discloses a combustion system, a gas engine and a combustion system design method, a second fuel injection hole sprays an oil jet to ignite a part of natural gas jets on the same side of the second fuel injection hole, and under the action of a vortex in a combustion chamber, with the second fuel injection hole continuously spraying the oil jet, a flame formed by the oil jet igniting the natural gas jets gradually becomes longer along the vortex direction, so that the oil jet sprayed by the second fuel injection hole ignites the natural gas jets on the side of the natural gas injector opposite to the fuel injector; the oil jet sprayed by the first fuel injection hole ignites the remaining natural gas jets, so that the oil jets sprayed by the fuel injector on both sides of a reference line can achieve the maximum ignition effect, all the natural gas jets are ignited by using the least oil jet, the ignition effect of igniting the natural gas by using the fuel is improved, the thermal efficiency is higher, and the emission is lower.

The invention discloses a cooperative control method for the air-fuel ratio, the injection opportunity and the cooling liquid temperature of a hydrogen fuel engine. The cooperative control method comprises the steps that S1, operation condition parameters and combustion state parameters of the hydrogen fuel engine are monitored; s2, based on the operation condition parameters, adaptively determining a target air-fuel ratio, a fuel injection opportunity and a cooling liquid temperature through a preset control strategy; s3, the combustion state and the engine operation condition are evaluated in real time through a closed-loop feedback control system, and the following cooperative adjustment is executed: the hydrogen supply amount is adjusted to maintain the target air-fuel ratio; the hydrogen injection time is adjusted, and the combustion phase is optimized. According to the cooperative control method for the air-fuel ratio, the injection opportunity and the cooling liquid temperature in the hydrogen fuel engine, the target air-fuel ratio, the hydrogen fuel injection opportunity and the engine cooling liquid temperature are comprehensively adjusted under a closed-loop feedback control framework, optimal control over the combustion process under different working conditions is achieved, and therefore the braking heat efficiency of the engine is improved, and the service life of the engine is prolonged. And pollutant emission is reduced, knocking is restrained, and the application requirement for efficient cleaning of the engine is met.

Deterioration diagnostic device for an exhaust gas control catalyst, wherein the deterioration diagnostic device is configured to diagnose deterioration of the exhaust gas control catalyst which is provided in an exhaust port of an internal combustion engine and is configured to store oxygen, and wherein the deterioration diagnostic device comprises: a downstream air-fuel ratio sensor (43) configured to detect an air-fuel ratio of an exhaust gas that has flowed out of the exhaust control catalyst; and a control device (31) configured to control an air-fuel ratio of an exhaust gas flowing into the exhaust control catalyst and to diagnose deterioration of the exhaust control catalyst based on an output from the downstream air-fuel ratio sensor (43), wherein the control device (31) is configured in a deterioration diagnostic process to diagnose deterioration of the exhaust control catalyst to alternately and repeatedly perform a rich process and a lean process, wherein the rich process is a process in which the air-fuel ratio of the exhaust gas flowing into the exhaust control catalyst is controlled to a rich air-fuel ratio that is richer than a stoichiometric air-fuel ratio, and wherein the lean process is a process in which the air-fuel ratio of the exhaust gas flowing into the exhaust control catalyst is controlled to a lean air-fuel ratio that is leaner than the stoichiometric air-fuel ratio. to switch from the rich process to the lean process when the amount of oxygen released by the exhaust gas control catalyst since the start of the rich process equals the first amount of oxygen, and to switch from the lean process to the rich process when the amount of oxygen stored in the exhaust gas control catalyst since the start of the lean process equals the second amount of oxygen, which is lower than the first amount of oxygen, and to determine that the exhaust gas control catalyst has deteriorated when the lean process is carried out and a frequency at which an output air-fuel ratio of the downstream air-fuel ratio sensor (43) is equal to the lean air-fuel ratio is equal to or greater than a predetermined frequency.

The present disclosure provides an engine intake system control method, device, computer program product, non-transitory computer-readable storage medium and electronic device. The method comprises: obtaining the air mass consumed by the cylinder; determining the air molar mass consumed by the cylinder according to the air mass consumed by the cylinder, the mass ratio of oxygen to air and the molecular weight of oxygen; and controlling the intake system of the engine based on the air molar mass consumed by the cylinder. The embodiments of the present disclosure are beneficial to realize accurate control of engine intake.

A method (100) for adjusting the timing of fuel injection into a combustion chamber (24) of a compression ignition engine (12), the method (100) comprising: Detect (102), via an electronic control (60), a request to generate zero torque by the motor; Switching off (104), via the electronic control (60), of the fuel supply to the combustion chamber (24) during the detected requirement to generate a torque of zero; Issue (106), via the electronic control (60), a command to inject a test quantity of fuel into the combustion chamber (24) while the detected requirement to generate zero torque exists; Assess (108), via the electronic control (60), a time delay (74) between the command given to inject the test fuel quantity and the start of the injection of the test fuel quantity; Determine (110), via the electronic control (60), a compensation for the assessed time delay (74); Detect (116), via the electronic control (60), a request to generate a positive torque by the motor and commands (118), via the electronic control (60), a shift in the timing of fuel injection into the combustion chamber (24) by the determined compensation during positive torque generation by the engine.

The application discloses a methanol engine control method, related device and methanol engine, and relates to the field of engine systems. By constructing a physical model of an air system, a first coupling influence compensation term representing the deterministic coupling influence between each actuator can be calculated in real time according to an expected value and an actual working condition. By introducing a nonlinear extended state observer, uncertainty factors, such as methanol injection amount deviation, pipeline carbon deposition, external environment changes and the like, which cannot be covered by the physical model, can be estimated in real time, and a second coupling influence compensation term can be generated. Finally, by a linear state error feedback control law, the first coupling influence compensation term and the second coupling influence compensation term are fused to form a dual-channel collaborative compensation architecture of physical model feedforward and nonlinear extended state feedback, and rapid and accurate control of an intake manifold pressure is realized. Through the cooperation of the physical model feedforward and the disturbance observation feedback, the control robustness of the intake manifold pressure and other key parameters is improved.

In an engine exhaust purification system that has a catalytic converter installed in the exhaust passage and controls the air-fuel ratio of the exhaust gas to set it to a target air-fuel ratio, the system accurately learns the target air-fuel ratio. [Solution] The engine exhaust gas purification device 100 includes a fuel injection valve 18 for supplying fuel to a combustion chamber 17, an exhaust passage 50 for discharging exhaust gas from the combustion chamber 17, a catalytic converter 51 provided on the exhaust passage 50 for purifying exhaust gas, a linear A / F sensor SW7 provided on the exhaust passage 50 downstream of the catalytic converter 51 and capable of detecting the air-fuel ratio of the exhaust gas, and a control device 60 that controls the fuel injection valve 18 based on the air-fuel ratio detected by the linear A / F sensor SW7 in order to set the air-fuel ratio of the exhaust gas to a target air-fuel ratio. The control device 60 calculates the range of fluctuation of the air-fuel ratio detected by the linear A / F sensor SW7 within a predetermined time and corrects the target air-fuel ratio based on this range of fluctuation.

The invention relates to a method for modeling an input current of a pump (110). The method comprises the steps of: (i) controlling the pump (110) to pressurize at least a portion of the evaporation system (100), (ii) determining a pressure profile in the evaporation system (100); and (iii) modeling a curve (350) of the input current of the pump (110) on the basis of the pressure curve by means of a model. The invention also relates to a corresponding controller (120).

The present application relates to a kind of fire diesel engine low temperature combustion efficiency promotion method.Fire diesel engine low temperature combustion efficiency promotion method, starting stage does not need to rely on external point heating equipment, preheating is carried out to intake and fuel respectively using exhaust waste heat and the integrated effect of repeated start, repeated heating under the control of multiple parameters, effectively guarantee the reliability of fast emergency start and emergency start under low temperature environment, through the integrated effect of ultrasonic atomization, multiple parameter collaborative control, effectively solve the problem of poor fuel atomization, mixture is not uniform, combustion is insufficient under low temperature condition, the combustion efficiency under low temperature condition is significantly improved, through the mutual coordination of residual humidity detection, ultrasonic auxiliary water removal unit in shutdown stage, the reliability of next start can be guaranteed.Therefore, the above-mentioned fire diesel engine low temperature combustion efficiency promotion method adapts to the scene demand of fire emergency without external power supply, fast response.

The invention discloses an air inlet control method of an engine and a vehicle. The method comprises the steps that target performance parameters of multiple air cylinders in the engine are obtained, the multiple air cylinders are divided into at least two air cylinder sets, and the target performance parameters at least comprise the exhaust gas recirculation degree; based on the target performance parameter of at least one cylinder in the same cylinder group, determining a target adjustment parameter of the cylinder group; and on the basis of the target adjustment parameters, the exhaust gas recirculation degree of at least one air cylinder in the air cylinder set is adjusted, so that the multiple air cylinders have the same exhaust gas recirculation degree. The technical problem that the consistency of the working states of different air cylinders of an engine in the prior art is poor is solved.

To provide a method for controlling a road vehicle during a slip of drive wheels.SOLUTION: The method has the steps of: detecting a slip of at least one drive wheel (3); and controlling, only during a slip of at least one drive wheel (3), a driving unit of the road vehicle (1) with a signaling law to obtain a cyclic operating irregularity which generates an abnormal vibration and / or abnormal noise.SELECTED DRAWING: Figure 1

A control device (125) for controlling an engine (102) of a vehicle (103) is disclosed together with a control system (101) comprising a control device (125), a vehicle (103), and a method (200, 500). The control device (125) comprises a control unit configured to cause the power generation of the engine (102) to shut down during movement of the vehicle (103) depending on at least one criterion being met, and to cause the power generation of the engine (102) to restart depending on at least one input signal indicating a need to restart the engine (102) to provide a required power output.The control unit is also configured to receive a target motor speed value that depends on a current drive shaft speed, and causes the motor (102) to maintain a speed not exceeding the target motor speed, which depends on the target motor speed value, for a period after receiving the at least one input signal and until a further signal is received indicating that the motor (102) has been reconnected to a drive shaft (104). The control unit is arranged to allow the motor speed to exceed the target motor speed after receiving the further signal.

There is provided a method (300) for controlling an injector (1) for an engine, the injector comprising an actuator (6) and a valve (2) which is engageable with a valve seat (5) of the injector, the valve comprising an elastomer seal (4) disposed at an end of the valve proximal to the valve seat, the actuator being configured to receive a drive signal (11.2) to move the valve towards and away from the valve seat to control injection of gaseous fuel into an associated engine combustion chamber, the method comprising: determining (302) a soak time, wherein the soak time is a time interval between a most recent power-off time of the engine and a subsequent power-on time of the engine; determining (304) a peak current (A1) and / or a duration (T2-T1) for an initial portion of the drive signal for the actuator as a function of the determined soak time; and applying (306) the initial portion of the drive signal to the actuator, using the peak current and / or for the duration, to move the valve from a closed state to an open state.

Disclosed herein is a work machine having a gas engine and a gas storage system having at least one gas storage tank. The controller is provided with a controller configured to determine a leakage condition within the gas storage system and / or the gas engine.