Work machine operators can experience significant levels of vibration. Many regulatory bodies have imposed restrictions on the vibration levels that an operator may be exposed to over time. To comply with these restrictions, an operator's time on a particular machine can be limited. Specifically, the operator may be required to cease operation of the machine once he has experienced a certain vibration level for a predetermined period of time. Alternatively, an active vibration management system may be employed in an attempt to reduce the average vibration level experienced by the operator and, therefore, prolong his allowed time on the machine.
Various systems have been proposed for actively reducing vibrations in a machine. Many of these systems involve sensing of vibrations produced in the machine and reducing the vibrations transferred from a vibration source to the frame of the machine. For example, U.S. Pat. No. 6,644,590 to Terpay et al. (“the '590 patent”), which issued on Nov. 11, 2003, describes an active system and method for reducing vibrations generated by a gearbox in a rotary wing aircraft. In this system, an active mount is connected between the gearbox and the airframe using hydraulic actuators to suspend the airframe from the gearbox. Based on output signals from various vibration sensors, hydraulic fluid may be supplied to the actuators to move the gearbox relative to the airframe. This motion may be controlled to minimize the transfer of vibrations from the gearbox to the frame.
While the system of the '590 patent may help reduce the vibrations transferred to certain machine components, the system has several shortcomings. For example, the system of the '590 patent cannot monitor or track average vibration levels experienced by an operator or component. Further, the system includes no predictive capability for determining the vibration response of a system to various operator inputs. In addition, the system does not include the capability of adjusting the response of a machine component to reduce the amount of vibration produced. Therefore, the system of the '590 patent may be unsuitable as a means for ensuring that an operator of a work machine does not experience a certain vibration level for greater than a permissible length of time.
The present disclosure is directed to overcoming one or more of the problems associated with the prior art active vibration reduction systems.