Automatic control system and method for joystick control-based construction equipment

• US 9,739,036 B2
• Filed: 11/20/2013
• Issued: 08/22/2017
• Est. Priority Date: 12/13/2012
• Status: Active Grant

• Current Assignee: HD Hyundai Construction Equipment Co., Ltd.
• Original Assignee: Hyundai Construction Equipment Co., Ltd.
• Inventors: Lee, Jong Chan, Choi, Lim Gook, Kwon, Young Min, Yim, Jong Hyung
• Primary Examiner(s): GOLDMAN, RICHARD A
• Application Number:
  US14/651,220
• Publication Number:
  US 20150308078A1
• Time in Patent Office: 1,371 Days
• Field of Search: 701 50, 74469, 74 47 R, 74491
• CPC Class Codes: E02F 3/42 Drives for dippers, buckets, dipper-arms or bucket-arms
• CPC Class Codes: E02F 3/434 providing automatic sequences of movements, e.g. automatic dumping or loading, automatic return-to-dig
• CPC Class Codes: E02F 3/437 providing automatic sequences of movements, e.g. linear excavation, keeping dipper angle constant
• CPC Class Codes: E02F 9/2004 Control mechanisms, e.g. control levers control levers per se G05G
• CPC Class Codes: E02F 9/2025 Particular purposes of control systems not otherwise provided for E02F3/16, E02F3/26, sub-groups of E02F3/43, E02F3/651, sub-groups of E02F3/84, E02F3/907, E02F5/145 take precedence
• CPC Class Codes: E02F 9/2203 Arrangements for controlling the attitude of actuators, e.g. speed, floating function
• CPC Class Codes: E02F 9/2228 including an electronic controller
• CPC Class Codes: E02F 9/2267 Valves or distributors position of valves arrangements on upper-structures E02F9/0875
• CPC Class Codes: E02F 9/2289 Closed circuit
• CPC Class Codes: E02F 9/2296 Systems with a variable displacement pump
• CPC Class Codes: E02F 9/265 with follow-up actions (e.g. control signals sent to actuate the work tool)
• CPC Class Codes: F15B 11/006 Hydraulic "Wheatstone bridge" circuits, i.e. with four nodes, P-A-T-B, and on-off or proportional valves in each link
• CPC Class Codes: F15B 11/161 with sensing of servomotor demand or load
• CPC Class Codes: F15B 13/085 Electrical controllers
• CPC Class Codes: F15B 13/086 Sensing means, e.g. pressure sensors
• CPC Class Codes: F15B 21/02 Servomotor systems with programme control derived from a store or timing device; Control devices therefor
• CPC Class Codes: F15B 2211/20546 variable capacity
• CPC Class Codes: F15B 2211/30575 in a Wheatstone Bridge arrangement (also half bridges)
• CPC Class Codes: F15B 2211/327 electrically or electronically
• CPC Class Codes: F15B 2211/6346 representing a state of input means, e.g. joystick position
• CPC Class Codes: F15B 2211/75 : Control of speed of the output member

Abstract

According to the present invention, a hydraulic system of construction equipment is implemented as a close center system, which converts an input signal of an electric or hydraulic joystick into a speed signal of a work apparatus, and controls a speed of the work apparatus regardless of an external load condition, thereby minimizing fatigue of a worker to improve work efficiency, improving a work apparatus operation ability of an unskilled person, and patterning standardized work to implement automation of construction equipment.

Claims

1. A system for automatically controlling construction equipment, to which a joystick is applied, based on a joystick control, comprising:

a hydraulic pump configured to discharge working fluid within a hydraulic tank and supply the working fluid to an actuator;

the actuator configured to drive a construction work apparatus with the working fluid of the hydraulic pump;

first electronic hydraulic control valves installed in a piston-side inlet flow path and a rod-side inlet flow path connected from the hydraulic pump to the actuator;

second electronic hydraulic control valves installed in a piston-side outlet flow path and a rod-side outlet flow path connected from the actuator to the hydraulic tank; and

a control unit configured to independently control the first electronic hydraulic control valves and the second electronic hydraulic control valves connected to the actuator,

wherein the system is implemented as a close center system without a bypass flow path connected from the hydraulic pump to the hydraulic tank by bypassing the actuator,

the control unit determines a speed of the actuator in proportion to a stroke by an operation of the joystick and controls the first electronic hydraulic control valves, the second electronic hydraulic control values and the hydraulic pump by using the speed of the actuator regardless of an external load condition, and

the control unit controls the hydraulic pump so as not to discharge a predetermined flow rate when the joystick is in a neutral stage.

2. The system of claim 1, wherein the joystick is an electric joystick, and

when an electric signal is generated by an operation of the electric joystick, the control unit controls the first electronic hydraulic control valves and the second electronic hydraulic control valves connected to the actuator by using the electric signal generated by the operation of the electric joystick.

3. The system of claim 1, wherein the joystick is a hydraulic joystick, and

the system further comprises a pressure sensor converting a pilot pressure formed by an operation of the hydraulic joystick into an electric signal, and

the control unit controls the first electronic hydraulic control valves and the second electronic hydraulic control valves connected to the actuator by using the electric signal generated by the pressure sensor.

4. The system of claim 2, wherein the control unit further includes a controller configured to convert a coded electric signal, which is in proportion to a stroke of the electric joystick into a speed signal, to control open/close of the first electronic hydraulic control valves and the second electronic hydraulic control valves, and to change a work speed of the construction work apparatus.

5. The system of claim 4, wherein an area of a flow path is variably controlled by the first electronic hydraulic control valves and the second electronic hydraulic control valves according to an operation quantity of the electric joystick.

6. The system of claim 2, wherein the control unit further includes a storage unit storing an electric signal and a speed signal generated according to an operation of the electric joystick in real time.

7. The system of claim 3, wherein the control unit further includes a controller configured to convert a coded electric signal, which is in proportion to a stroke of the hydraulic joystick into a speed signal, to control open/close of the first electronic hydraulic control valves and the second electronic hydraulic control valves, and to change a work speed of the construction work apparatus.

8. The system of claim 3, wherein the control unit further includes a storage unit storing an electric signal and a speed signal generated according to an operation of the hydraulic joystick in real time.

9. The system of claim 7, wherein an area of a flow path is variably controlled by the first electronic hydraulic control valves and the second electronic hydraulic control valves according to an operation quantity of the hydraulic joystick.

10. The system of claim 1, wherein the control unit further comprises a storage unit configured to store the input signal generated by the operation of the joystick and the speed signal controlling the work speed of the construction work apparatus for a specific time period,

wherein the control unit is configured to control the work speed of the construction work apparatus using the input signal and the speed signal previously stored in the storage unit.

11. The system of claim 1, comprising a plurality of actuators and a storage unit configured to store the number of driven actuators and information on operation quantity of the joystick,

wherein the control unit is configured to control a speed of each of the actuators according to the number of driven actuators and the information on the operation quantity of the joystick stored in the storage unit.

12. The system of claim 1, wherein the control unit is configured to store an operation signal of the joystick in response to a request of automatic excavation function of the construction work apparatus and to generate control signals of the hydraulic pump and the first and second electronic hydraulic control valves by using the previously stored operation signal of the joystick.