Abstract: A swing drive system for an excavator is provided which utilizes a prime mover mechanically connected to a first hydraulic pump/motor and a second hydraulic pump/motor mechanically connected to a swing mechanism. The system includes a hydraulic circuit connecting a hydraulic fluid reservoir, a hydraulic accumulator, the first hydraulic pump/motor, and the second hydraulic pump/motor. The system is operable in one mode where the second hydraulic pump/motor acts as a pump to retard movement of the swing mechanism and pressurized hydraulic fluid from the second hydraulic pump/motor is pumped into the hydraulic accumulator. The system is operable in another mode where the pressurized fluid from the hydraulic accumulator is used to assist the prime mover in driving hydraulic consumers, including the swing drive.

Abstract: A device, system and method for harvesting electrical power from hydraulic fluid of a hydraulic system determines at least one of hydraulic fluid flow or hydraulic fluid pressure in the hydraulic system. Based on rules and the determined at least one of the hydraulic fluid flow or hydraulic fluid pressure, an expected conversion efficiency of the power conversion device and an expected rectified power to be generated from the received input power by the power conversion device are determined. From the expected rectified power a potential conversion efficiency of the power conversion device is determined, and the power conversion device is commanded to produce the expected rectified power when the potential conversion efficiency is greater than or equal to the expected conversion efficiency. When the potential conversion efficiency is less than the expected conversion efficiency, the rules are updated.

Abstract: A device, system and method for harvesting electrical power from hydraulic fluid of a hydraulic system determines at least one of hydraulic fluid flow or hydraulic fluid pressure in the hydraulic system. Based on rules and the determined at least one of the hydraulic fluid flow or hydraulic fluid pressure, an expected conversion efficiency of the power conversion device and an expected rectified power to be generated from the received input power by the power conversion device are determined. From the expected rectified power a potential conversion efficiency of the power conversion device is determined, and the power conversion device is commanded to produce the expected rectified power when the potential conversion efficiency is greater than or equal to the expected conversion efficiency. When the potential conversion efficiency is less than the expected conversion efficiency, the rules are updated.

Abstract: A control system for a working machine that includes a power consumer (14) includes a prime mover (12), an energy storage unit (24) for storing energy, an auxiliary power unit (20) for generating power or consuming power, the auxiliary power unit (20) having a first connection (20a) coupled to the prime mover (12) and a second connection couplable to the energy storage unit (24). A controller (18) operatively coupled to the prime mover (12) and operatively couplable to the power consumer (14) is configured to estimate a required power of the power consumer (14), and to command the prime mover (14) to operate at an optimal operating point that produces the estimated required power.

Abstract: A swing drive system for an excavator is provided which utilizes a prime mover mechanically connected to a first hydraulic pump/motor and a second hydraulic pump/motor mechanically connected to a swing mechanism. The system includes a hydraulic circuit connecting a hydraulic fluid reservoir, a hydraulic accumulator, the first hydraulic pump/motor, and the second hydraulic pump/motor. The system is operable in one mode where the second hydraulic pump/motor acts as a pump to retard movement of the swing mechanism and pressurized hydraulic fluid from the second hydraulic pump/motor is pumped into the hydraulic accumulator. The system is operable in another mode where the pressurized fluid from the hydraulic accumulator is used to assist the prime mover in driving hydraulic consumers, including the swing drive.

Abstract: A swing drive system (11) for an excavator is provided which utilizes a prime mover (20) mechanically connected to a first hydraulic pump/motor (30) and a second hydraulic pump/motor (32) mechanically connected to a swing mechanism (70). The system includes a hydraulic circuit (31) connecting a hydraulic fluid reservoir (42), a hydraulic accumulator (40), the first hydraulic pump/motor (30), and the second hydraulic pump/motor (32). The system is operable in one mode where the second hydraulic pump/motor acts as a pump to retard movement of the swing mechanism and pressurized hydraulic fluid from the second hydraulic pump/motor is pumped into the hydraulic accumulator. The system is operable in another mode where the pressurized fluid from the hydraulic accumulator is used to assist the prime mover in driving hydraulic consumers (62,64,66), including the swing mechanism.

Abstract: A control system for a working machine that includes a power consumer (14) includes a prime mover (12), an energy storage unit (24) for storing energy, an auxiliary power unit (20) for generating power or consuming power, the auxiliary power unit (20) having a first connection (20a) coupled to the prime mover (12) and a second connection couplable to the energy storage unit (24). A controller (18) operatively coupled to the prime mover (12) and operatively couplable to the power consumer (14) is configured to estimate a required power of the power consumer (14), and to command the prime mover (14) to operate at an optimal operating point that produces the estimated required power.

Abstract: Proposed is a method for controlling pressure supplied by a hydraulic pump that includes determining whether there is an impending overshoot in a value of the pressure supplied by the hydraulic pump and engaging a peak and hold controller when it is determined that there is an impending overshoot in a value of the pressure supplied by the hydraulic pump, thereby reducing or eliminating supplied pressure overshoot.

Abstract: A swing drive system (11) for an excavator is provided which utilizes a prime mover (20) mechanically connected to a first hydraulic pump/motor (30) and a second hydraulic pump/motor (32) mechanically connected to a swing mechanism (70). The system includes a hydraulic circuit (31) connecting a hydraulic fluid reservoir (42), a hydraulic accumulator (40), the first hydraulic pump/motor (30), and the second hydraulic pump/motor (32). The system is operable in one mode where the second hydraulic pump/motor acts as a pump to retard movement of the swing mechanism and pressurized hydraulic fluid from the second hydraulic pump/motor is pumped into the hydraulic accumulator. The system is operable in another mode where the pressurized fluid from the hydraulic accumulator is used to assist the prime mover in driving hydraulic consumers (62,64,66), including the swing mechanism.