Swing deceleration control system

10:

• The working machine of claim 1, wherein:
• the controller is configured to detect the inertia caused pivotal motion of the main frame and boom assembly relative to the undercarriage continuing after the operator input actuator is moved to the neutral position by:
• detecting whether the operator input actuator is in the neutral position;
• and
• detecting whether the main frame and boom assembly are pivoting about the pivot axis relative to the undercarriage.

13:

• The working machine of claim 1, further comprising:
• a hydraulic pump for supplying pressurized hydraulic fluid to the swing hydraulic motor;
• an electro-hydraulic directional control valve arranged to receive the pressurized hydraulic fluid from the hydraulic pump and to control a direction and flow rate of the pressurized hydraulic fluid to a selected one of the first and second pressure ports of the swing hydraulic motor;
• and
• first and second fluid supply lines connecting the electro-hydraulic directional control valve to the first and second pressure ports, respectively.

14:

• The working machine of claim 13, wherein:
• the electro-hydraulic directional control valve is also the adjustable control valve;
• and
• the controller is configured to send the command signal to the electro-hydraulic directional control valve to direct the electro-hydraulic directional control valve to send the pressurized hydraulic fluid to one of the first and second pressure ports to at least partially offset the detected inertia caused pivotal motion.

15:

• The working machine of claim 13, further comprising:
• a bypass line connecting the first and second fluid supply lines and thereby communicating the first and second pressure ports;
• and
• wherein the adjustable control valve includes an adjustable orifice valve disposed in the bypass line.

17:

• A method of operating a working machine, the working machine including an undercarriage including a plurality of ground engaging units for engaging a ground surface, a main frame, a swing hydraulic motor configured to pivot the main frame about a pivot axis relative to the undercarriage, a boom assembly extending from the main frame, an operator input actuator for generating an operator input signal directing pivotal movement of the main frame and boom assembly about the pivot axis relative to the undercarriage, and an adjustable control valve communicated with first and second pressure ports of the swing hydraulic motor, the method comprising:
• detecting with a motion detection sensor a pivotal movement of the main frame and boom assembly about the pivot axis relative to the undercarriage and generating with the motion detection sensor a swinging motion signal representative of the pivotal movement of the main frame and boom assembly about the pivot axis relative to the undercarriage;
• receiving the operator input signal and the swinging motion signal with an automatic controller;
• detecting with the automatic controller an inertia caused pivotal motion of the main frame and boom assembly relative to the undercarriage continuing after the operator input actuator is moved to a neutral position;
• and
• sending a command signal from the automatic controller to the adjustable control valve to reduce the inertia caused pivotal motion.

18:

• The method of claim 17, wherein:
• the adjustable control valve is a hydraulic fluid supply control valve communicated with the first and second pressure ports of the swing hydraulic motor and configured to control a flow direction and a flow rate of hydraulic fluid from a hydraulic pressure source to the swing hydraulic motor;
• and
• the sending includes sending the command signal to the hydraulic fluid supply control valve to direct the hydraulic fluid supply control valve to send a hydraulic fluid flow to one of the first and second pressure ports to at least partially offset the detected inertia caused pivotal motion.

19:

• The method of claim 17, wherein:
• the adjustable control valve includes an adjustable orifice valve disposed in a bypass line communicating the first and second pressure ports of the swing hydraulic motor;
• and
• the sending includes sending the command signal to the adjustable orifice valve to adjust a pressure restriction between the first and second pressure ports in the bypass line to at least partially relieve a pressure differential between the first and second pressure ports caused by the inertia caused pivotal motion.