Abstract: A computer-implemented method for predicting external resistive forces encountered by an industrial machine includes (a) predicting by a first model a resistive force applied to an industrial machine from an external material using previously collected sensor data, (b) predicting by a second model that is different from the first model an error of the resistive force predicted by the first model using the previously collected sensor data and the resistive force predicted by the first model, and (c) determining a corrected prediction of the resistive force by combining the resistive force predicted by the first model with the error predicted by the second model.

Abstract: In some examples, a method for estimating the cetane number of a fuel includes receiving current engine operating condition measurements from a compression ignition (CI) engine using the fuel, and determining a value for a current engine performance indicator. The method further includes determining a projected engine performance indicator value for the CI engine based on the current estimated cetane number, current engine control signals and the current engine operating condition measurements. The method also includes determining that a difference between the value of the current engine performance indicator and the projected engine performance indicator value is greater than a threshold amount. If the difference is greater than the threshold amount, the method also includes determining a new estimated cetane number.

Abstract: The subject matter of this specification can be embodied in, among other things, a method for operating a hydraulic free piston engine includes receiving, at an engine controller for a hydraulic free piston engine, an energy parameter that is representative of an amount of fluid energy to be output by the engine, and a measured fluid pressure value of a fluid load of the engine, determining a piston trajectory of a piston within a hydraulic chamber of the engine, determining a fuel volume value and a servo valve actuation parameter, based on the energy parameter and the measured fluid pressure value, providing a fuel control signal to a fuel control device of the engine based on the fuel volume value, and providing, based on the servo valve actuation parameter and the piston trajectory, a servo valve control signal to a servo valve.

Abstract: A free-piston (“FP”) engine is a type of internal combustion engine with no crankshaft, so that its piston trajectory is no longer constrained by the mechanical linkage. FP engines have a high potential in terms of energy saving given their simple structure, high modularity and high efficiency, among other attributes. One of the technical barriers that affect FP engine technology is a lack of precise piston trajectory control. For example, the presence of a transient period after a single combustion event can prevent the engine from continuous firing. The present subject matter provides a control scheme that can utilize a reference and control signal shifting technique to modify the tracking error and the control signal to reduce the transient period.

Abstract: Motion control of a hydraulic free-piston engine is achieved in order to enable advanced combustions such as low temperature combustion. To accomplish this, an active controller acts as a virtual crankshaft, which causes a piston to follow a reference trajectory using energy from a storage element. Given the periodic nature of free-piston engine motion, an advanced controller of the present invention is preferably of robust repetitive type that is capable of tracking periodic reference signals.

Abstract: The subject matter of this specification can be embodied in, among other things, a method for operating a hydraulic free piston engine includes receiving, at an engine controller for a hydraulic free piston engine, an energy parameter that is representative of an amount of fluid energy to be output by the engine, and a measured fluid pressure value of a fluid load of the engine, determining a piston trajectory of a piston within a hydraulic chamber of the engine, determining a fuel volume value and a servo valve actuation parameter, based on the energy parameter and the measured fluid pressure value, providing a fuel control signal to a fuel control device of the engine based on the fuel volume value, and providing, based on the servo valve actuation parameter and the piston trajectory, a servo valve control signal to a servo valve.

Abstract: An injector is designed to provide continuously variable injection rate shaping. With a hydro-mechanical internal feedback mechanism, injector needle position can be determined by controlling a feedback valve's on/off timing. According to the needle position, an injection needle valve opening can be controlled, and then the injection flow rate can be delivered proportionally. Also in accordance with the present invention a CRDI systems are provided including injectors of the present invention, wherein results demonstrate that injector designs of the present invention not only achieve rate shaping capability but also solve the above-noted problems of the current CRDI system. Finally, an iterative learning controller has also been developed to track the desired injection rate, and an injection rate estimator is designed to realize a cycle to cycle feedback control.

Abstract: A free-piston (“FP”) engine is a type of internal combustion engine with no crankshaft, so that its piston trajectory is no longer constrained by the mechanical linkage. FP engines have a high potential in terms of energy saving given their simple structure, high modularity and high efficiency, among other attributes. One of the technical barriers that affect FP engine technology is a lack of precise piston trajectory control. For example, the presence of a transient period after a single combustion event can prevent the engine from continuous firing. The present subject matter provides a control scheme that can utilize a reference and control signal shifting technique to modify the tracking error and the control signal to reduce the transient period.

Abstract: An injector is designed to provide continuously variable injection rate shaping. With a hydro-mechanical internal feedback mechanism, injector needle position can be determined by controlling a feedback valve's on/off timing. According to the needle position, an injection needle valve opening can be controlled, and then the injection flow rate can be delivered proportionally. Also in accordance with the present invention a CRDI systems are provided including injectors of the present invention, wherein results demonstrate that injector designs of the present invention not only achieve rate shaping capability but also solve the above-noted problems of the current CRDI system. Finally, an iterative learning controller has also been developed to track the desired injection rate, and an injection rate estimator is designed to realize a cycle to cycle feedback control.

Abstract: Motion control of a hydraulic free-piston engine is achieved in order to enable advanced combustions such as low temperature combustion. To accomplish this, an active controller acts as a virtual crankshaft, which causes a piston to follow a reference trajectory using energy from a storage element. Given the periodic nature of free-piston engine motion, an advanced controller of the present invention is preferably of robust repetitive type that is capable of tracking periodic reference signals.

Abstract: Valve lift in an internal combustion engine is controlled by an electro-hydraulic actuation mechanism including a selectively actuable hydraulic feedback circuit.

Abstract: A drive piston assembly is provided that is operable to selectively open a poppet valve. The drive piston assembly includes a cartridge defining a generally stepped bore. A drive piston is movable within the generally stepped bore and a boost sleeve is coaxially disposed with respect to the drive piston. A main fluid chamber is at least partially defined by the generally stepped bore, drive piston, and boost sleeve. First and second feedback chambers are at least partially defined by the drive piston and each are disposed at opposite ends of the drive piston. At least one of the drive piston and the boost sleeve is sufficiently configured to move within the generally stepped bore in response to fluid pressure within the main fluid chamber to selectively open the poppet valve. A valve actuator assembly and engine are also provided incorporating the disclosed drive piston assembly.

Abstract: A valve actuator assembly for an engine includes a movable poppet valve, and movable first and second spool valves. The assembly also includes an intermediate channel interconnecting the first and second spool valve, a driving channel, and a first and second feedback channel interconnecting the second spool valve and the poppet valve. The valve actuator assembly includes an actuator cooperating with the first spool valve to position the first spool valve to selectively allow high pressure fluid flow to the second spool valve and the driving channel to position the engine valve. The valve actuator assembly further includes a first and second on/off valve in respective fluid communication with the first feedback channel and the second feedback channel to selectively exhaust the first and second feedback channel to control motion of the second spool valve. The second spool valve includes a detent feature operable to maintain the second spool valve in a center biased position.

Abstract: A drive piston assembly is provided that is operable to selectively open a poppet valve. The drive piston assembly includes a cartridge defining a generally stepped bore. A drive piston is movable within the generally stepped bore and a boost sleeve is coaxially disposed with respect to the drive piston. A main fluid chamber is at least partially defined by the generally stepped bore, drive piston, and boost sleeve. First and second feedback chambers are at least partially defined by the drive piston and each are disposed at opposite ends of the drive piston. At least one of the drive piston and the boost sleeve is sufficiently configured to move within the generally stepped bore in response to fluid pressure within the main fluid chamber to selectively open the poppet valve. A valve actuator assembly and engine are also provided incorporating the disclosed drive piston assembly.

Abstract: A direct injection controlled auto-ignition engine is operated at steady state, within a homogeneous charge compression-ignition (HCCI) load range and with fuel-air-diluent mixtures at predetermined conditions, for each speed and load, of engine control inputs, including at least fueling mass flow rate, injection timing (FI), spark timing (SI) and exhaust recompression obtained by negative valve overlap (NVO). During load change rates below a predetermined threshold, SI, FI and NVO change rates are synchronized to current changes in the fueling mass flow rate. For fast load increases above the threshold, the cylinder charge is temporarily enriched by increasing the percentage of residual gas or reducing the percentage of fresh air mass in the charge sufficiently to maintain auto-ignition temperature during the load change. This may be done by delaying NVO action for a predetermined speed-dependent number of engine cycles.

Abstract: A method is provided for control of transition between combustion modes of a direct-injection engine operable in a homogeneous charge compression ignition (HCCI) mode at lower loads and a spark ignition flame propagation (SI) mode at higher loads. The engine includes a variable valve actuation system including two-step high and low lift valve actuation and separate cam phasing for both intake and exhaust valves. The method includes operating the engine at steady state, with fuel-air-exhaust gas mixtures at predetermined conditions, for each speed and load, and controlling the engine during mode changes between the HCCI mode and the SI mode by switching the exhaust and intake valves between low lift for HCCI operation and high lift for SI operation.

Abstract: A direct injection controlled auto-ignition engine is operated at steady state, within a homogeneous charge compression-ignition (HCCI) load range and with fuel-air-diluent mixtures at predetermined conditions, for each speed and load, of engine control inputs, including at least injection timing (FI), spark timing (SI), throttle position, exhaust gas recirculation (EGR) valve setting and exhaust recompression obtained by negative valve overlap (NVO). During engine speed transients, the control inputs are synchronized to changes in the current engine speed, and also with any concurrent changes in the engine fueling rate. Inputs that are inactive during all or part of a speed change have a zero change rate while inactive. The method maintains robust auto-ignition combustion during speed transients with constant or variable fueling rates and with or without load changes.

Abstract: A method is provided for control of a direct-injection engine operated with controlled auto-ignition (HCCI) during load transient operations between modes of lean combustion low load (HCCI/Lean) and stiochiometric combustion medium load (HCCI/Stoich.). The method includes 1) operating the engine at steady state, within a homogeneous charge compression-ignition (HCCI) load range, with fuel-air-exhaust gas mixtures at predetermined conditions, for each speed and load, and controlling the engine during changes of operating mode between one to another of the HCCI/Stoich. medium load mode and the HCCI/Lean lower load mode by synchronizing change rates of predetermined controlled inputs to the current engine fueling change rate.

Abstract: Valve lift in an internal combustion engine is controlled by an electro-hydraulic actuation mechanism including a selectively actuable hydraulic feedback circuit.

Abstract: A valve actuator assembly for an engine includes a movable poppet valve, and movable first and second spool valves. The assembly also includes an intermediate channel interconnecting the first and second spool valve, a driving channel, and a first and second feedback channel interconnecting the second spool valve and the poppet valve. The valve actuator assembly includes an actuator cooperating with the first spool valve to position the first spool valve to selectively allow high pressure fluid flow to the second spool valve and the driving channel to position the engine valve. The valve actuator assembly further includes a first and second on/off valve in respective fluid communication with the first feedback channel and the second feedback channel to selectively exhaust the first and second feedback channel to control motion of the second spool valve. The second spool valve includes a detent feature operable to maintain the second spool valve in a center biased position.