Adaptive open loop control to reduce engine induced vibration and noise

Methods and systems are provided for controlling an active vibration system. In one embodiment, a method of controlling an active vibration system associated with an engine is provided. The method includes: receiving engine parameters indicating one or more engine operating conditions; determining an operating mode of the active vibration system to be at least one of a sensing mode and a force generation mode based on the engine parameters; and selectively controlling the active vibration system based on the operating mode.

TECHNICAL FIELD

The technical field generally relates to control methods and systems for engine mount systems, and more particularly relates to open loop control methods and systems for engine mount systems.

BACKGROUND

Active vibration control systems are used to reduce or cancel noise and vibrations induced by internal combustion engines of vehicles. Active vibration control systems utilize active actuators, such as active engine mounts, to cancel the engine induced vibrations.

One such active engine mount comprises a spring-mass system such as an electromagnetic actuator having an electromagnet and piston. The electromagnetic actuator is electromagnetically driven and operable to generate a neutralizing force in response to forces transmitted to the chassis or body it is mounted on. However, in order to effectively cancel the transmitted or resultant forces, the neutralizing force must be tuned to the amplitude and frequency of the transmitted force. While numerous methods and apparatuses have been developed for generating such a neutralizing force, in all known developments, generating the neutralizing force is achieved independently. That is, independent mechanisms (e.g., additional sensors) are employed in order to tune the frequency of the neutralizing force to the frequency of the resultant forces (which is a function of the rotational speed of the crankshaft). Such independent mechanisms often require expensive and complex control units to effectively cancel engine induced forces.

Accordingly, it is desirable to provide improved methods and systems for controlling an active engine mount. In addition, it is desirable to provide methods and systems for controlling an active engine mount without the need for additional sensors. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.

SUMMARY

Methods and systems are provided for controlling an active vibration system. In one embodiment, a method of controlling an active vibration system associated with an engine is provided. The method includes: receiving engine parameters indicating one or more engine operating conditions; determining an operating mode of the active vibration system to be at least one of a sensing mode and a force generation mode based on the engine parameters; and selectively controlling the active vibration system based on the operating mode.

In another embodiment, an engine mount system is provided. The system includes an active vibration system; a switch associated with the active vibration system; and a control module. The control module determines an operating mode of the active vibration system to be at least one of a sensing mode and a force generation mode, and that generates a control signal to the switch based on the operating mode.

DETAILED DESCRIPTION

The following detailed description is merely exemplary in nature and is not intended to limit the application and uses. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. As used herein, the term module refers to any hardware, software, firmware, electronic control component, processing logic, and/or processor device, individually or in any combination, including without limitation: application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.

Referring now toFIG. 1, a vehicle10is shown to include an engine mount system12in accordance with various embodiments. Although the figures shown herein depict an example with certain arrangements of elements, additional intervening elements, devices, features, or components may be present in actual embodiments. It should also be understood thatFIG. 1is merely illustrative and may not be drawn to scale.

The vehicle10is shown having an internal combustion engine13mounted to a chassis/body member14. The chassis/body member14is supported by a suspension system16. Those skilled in the art will recognize that the suspension system16may include such components as springs, shock absorbers, tires, etc., which are not shown for purposes of clarity. The internal combustion engine13includes an engine block18configured to rotatably support a crankshaft20. A sensor22operates to provide an observed crankshaft angle value to an engine control module24. The engine control module24controls the internal combustion engine13based on the crankshaft angle and sensor signals received from other sensors (not shown) of the internal combustion engine13.

An active vibration system15operates to cancel vibrations imparted to the chassis/body member14by the internal combustion engine13. For example, the active vibration system15can include active engine mounts26that support the internal combustion engine13on the chassis/body member14. Alternatively, the active vibration system15can include active tuned absorbers, shown in phantom at27, that are coupled to the chassis/body member14. As can be appreciated, the active vibration system15can include any active vibration system that includes, for example, an actuator having a moving mass surrounded by a coil, and is not limited to the present examples.

The active vibration system15is electronically controlled by a control module30. A switch32is disposed between the active vibration system15and the control module30. The switch32is controlled by the control module30to at least one of a first position and a second position. When controlled to the first position, the switch32permits control signals generated by the control module30to pass from the control module30to the active vibration system15, to energize the active vibration system15.

When controlled to the second position, the switch32permits current signals generated by the active vibration system15to pass from the active vibration system15to the control module30. The current is generated, for example, by excitation of the moving mass that is induced by vibration and/or road input, when the active vibration system15is not energized. For example, the motion of the moving mass causes a magnetic flux through a surrounding coil that causes current in the coil. The current in the coil may be correlated with an engine inducted vibration level. The switch32permits flow of the current from the current coil to the control module30, and thus the active vibration system15themselves act as sensors of the vibration imparted to the chassis/body member14.

The control module30controls the switch32based on an operating mode of the active vibration system15. As will be discussed in more detail below, the control module30determines the operating mode to be at least one of a sensing mode and a force generation mode based on engine parameters. The engine parameters may be received from sensors of the engine mount system12or from the engine control module24.

When the control module30determines the operating mode to be the sensing mode, the control module30receives the current signal generated by the active vibration system15. When the control module30determines the operating mode to be the force generation mode, the control module30generates control signals to the active vibration system15based on information determined from the received current signals. Thus, the control module30operates in an adaptive open loop mode.

Referring now toFIG. 2and with continued reference toFIG. 1, a functional block diagram illustrates various embodiments of the control module30of the engine mount system12. Various embodiments of the control module30according to the present disclosure may include any number of sub-modules. As can be appreciated, the sub-modules shown inFIG. 2may be combined and/or further partitioned to similarly control the active vibration system15based on adaptive open loop methods. Inputs to the control module30may be received from the active vibration system15, received from other control modules (e.g., the engine control module24) of the vehicle10, and/or determined by other sub-modules (not shown) of the control module30. In various embodiments, the control module30includes a mode determination module40, an adaptation module42, a switch control module44, an active vibration control module46, and a tables datastore48.

The tables datastore48stores one or more tables (e.g., lookup tables) that indicate a force for controlling the active vibration system15. In various embodiments, the tables can be interpolation tables that are defined by one or more indexes. A force value provided by at least one of the table indicates an amount of force needed to suppress or cancel a vibration level of the internal combustion engine13. For example, one or more tables can be indexed by engine parameters such as, but not limited to, engine crank position, engine speed, engine torque, gear state, and engine temperature and can provide a vibration level. In addition, at least one table can be indexed by the vibration level and can provide the force value. Thus, the force value indicates an amount of force needed to suppress or cancel a particular vibration level generated at particular engine crank position, engine speed, engine torque, gear state, and engine temperature.

The mode determination module40receives as input engine parameters50indicating one or more operating conditions of the internal combustion engine13. The engine parameters50can indicate an engine operating mode (e.g., a reduced power mode, or other mode), a particular engine crank position, engine speed, engine torque, gear state, or engine temperature, or any other condition of the engine that may affect engine vibration.

Based on the engine parameters50, the mode determination module40determines an operating mode52of the active vibration system15to be at least one of a sensing mode and a force generation mode. For example, the mode determination module40determines the mode to be the force generation mode based on the engine operating mode. In another example, the mode determination module40determines the mode to be the sensing mode when the mode is not the force generation mode and based on particular engine parameters. In yet another example, the mode determination module40determines the mode to be the sensing mode when the mode is not the force generation mode and based on periodic time intervals. As can be appreciated, the mode determination module40may determine the operating mode52based on other conditions and is not limited to the present examples.

The switch control module44receives as input the operating mode52. When the operating mode52indicates the sensing mode, the switch control module44generates a switch control signal54to the switch32such that the active vibration system15can be operated in a sensing mode. When the operating mode52indicates the actuating mode, the switch control module44generates a switch control signal54to the switch such that the active vibration system15can be operated in a force generating mode.

The adaptation module42receives as input the operating mode52. The adaptation module42updates the tables stored in the tables datastore48based on the operating mode52. For example, when the operating mode52indicates the sensing mode, the adaptation module42monitors a current signal56received from the active vibration system15. Substantially simultaneously, the adaptation module42monitors engine parameters58including, but not limited to, engine speed, engine torque, a gear state, engine temperature, and the crankshaft signal received from the engine control module. The adaptation module42determines from the current signal56an engine induced vibration level60and associates the determined vibration level60with the monitored engine speed, engine torque, a gear state, engine temperature, and/or the crankshaft signal. The adaptation module42updates the tables of the tables datastore48with the determined engine induced vibration level60based on the associated engine speed, engine torque, gear state, engine temperature, and/or crankshaft angle. In another example, when the operating mode52is the actuation mode, the adaptation module42does not update the tables of the tables datastore48.

The active vibration control module46receives as input the operating mode52. The active vibration control module46generates an engine mount control signal62to the active vibration system15based on the operating mode52. For example, when the operating mode52indicates the sensing mode, no control signal is sent to the active vibration system15. In another example, when the operating mode52indicates the actuation mode, engine parameters64are received and a force value66is determined from the tables of the tables datastore48based on the values of the engine parameters64(e.g., by performing a lookup function on the tables to determine a vibration level using the engine parameters and by correlating the vibration level with a force value). The control signal62is generated to the active vibration system15based on the force value66to control the vibration and noise created by the internal combustion engine13.

Referring now toFIG. 3, and with continued reference toFIGS. 1 and 2, a flowchart illustrates an active vibration control method that can be performed by one or more components of the engine mount system12ofFIGS. 1 and 2in accordance with various embodiments. As can be appreciated in light of the disclosure, the order of operation within the method is not limited to the sequential execution as illustrated inFIG. 3, but may be performed in one or more varying orders as applicable and in accordance with the present disclosure.

As can further be appreciated, the method ofFIG. 3may be scheduled to run at predetermined time intervals during operation of the vehicle10and/or may be scheduled to run based on predetermined events.

In one example, the method may begin at100. The engine parameters50are received at110. The operating mode52is determined based on the engine parameters50at120. If the operating mode52is the sensing mode at130, the method proceeds to step140. If, however, the operating mode52is not the sensing mode, rather the operating mode52is the force generation mode at130, the method proceeds to step210.

At140, when in the sensing mode, the switch control signal54is generated to activate the switch32such that sensing of the active vibration system15can occur. The current signal56from the active vibration system15is monitored at150. The engine parameters58are monitored at160. The vibration level60is determined based on the current signal56at170and associated with the monitored engine parameters58at180. The tables in the tables datastore48are updated based on the determined vibration level60and the associated engine parameters58at190. Thereafter, the method may end at200.

At210, however, when in the force generation mode, the switch control signal54is generated to activate the switch32such that force can be generated by the active vibration system15to cancel or suppress engine noise and vibration. The engine parameters64are monitored at220. The force value66is determined from the tables of the tables datastore48based on the engine parameters64at230, and the engine mount control signal62is generated based on the force value66at240. Thereafter, the method may end at200.