Apparatus and method for controlling actuators of hydraulic construction equipment

• US 5,845,223 A
• Filed: 10/08/1997
• Issued: 12/01/1998
• Est. Priority Date: 07/02/1993
• Status: Expired due to Fees

• Current Assignee: Volvo Construction Equipment Korea Co., Ltd. (AB Volvo)
• Original Assignee: Samsung Heavy Industries Company Limited (Samsung Group)
• Inventors: Song, Myung-Hoon
• Primary Examiner(s): Zanelli, Michael
• Assistant Examiner(s): PIPALA, EDWARD J
• Application Number:
  US08/946,714
• Time in Patent Office: 419 Days
• Field of Search: 701/50, 172/2, 37/234-236, 414/699, 414/708
• US Class Current: 701/50
• 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 9/2235 including an electronic controller
• CPC Class Codes: E02F 9/2292 Systems with two or more pumps
• CPC Class Codes: E02F 9/2296 Systems with a variable displacement pump

Abstract

An apparatus and a method for controlling a moving speed of each bucket and a moving speed ratio between each bucket, to be proportional to a degree of operation of each operation indicator and an operation ratio between each operation indicator, regardless of changes in various working conditions or load pressures. The apparatus receives an operation command from an input portion and converts the operation command into an operation signal, calculates a required discharge oil amount of a pump, which is proportional to the operation signal and a required moving speed of an actuator and which is proportional to the degree of operation and the operation ratio of the operation signal, adjusts the required discharge oil amount and the required moving speed based on a maximum dischargeable oil amount of the pump, subtracts a real discharge oil amount and a real moving speed from the adjusted discharge oil amount and the adjusted moving speed, and controls the discharge oil amount of the pump according to the control signal from the subtraction, and controls the moving speed of the actuator according to the subtraction control signal.

Claims

1. A method for controlling actuators of hydraulic construction equipment, said actuators supplied with oil from pumps through electrically controllable proportion valves, each pump defined as having left and right hand sides, said method comprising the steps of:

(1) calculating a necessary discharge oil amount required for the moving of said actuators according to a first reference input signal for controlling an oil amount of said pumps, a second reference input signal for controlling a moving speed of said actuators, and maximum dischargeable oil amount signal of said pumps;

(2) determining a required discharge oil amount for the left-hand side of the pump according to a comparison between a sum of a necessary oil amounts required for the moving of the actuators corresponding to the left-hand side of the pump and a maximum dischargeable oil amount of the left-hand side of the pump;

(3) determining a required discharge oil amount f or the right-hand side of the pump according to a comparison between a sum of a necessary oil amounts required for the moving of the actuators corresponding to the right-hand side of the pump and a maximum dischargeable oil amount of the right-hand side of the pump;

(4) generating a third reference input signal for controlling the oil amount of said pumps and a fourth reference input signal for controlling the moving speed of said actuators according to said required discharge oil amounts of said second and third steps; and

(5) controlling the oil amount of said pumps and the moving speed of said actuators by means of the third and fourth reference input signals generated in said fourth step being applied to said proportion valves.

2. The method of claim 1, wherein said second step comprises the steps of:

(1) comparing a required discharge oil amount of the left-hand side of the pump with a maximum dischargeable oil amount of the left-hand side of the pump; and

(2) setting said required discharge oil amount to be said maximum dischargeable oil amount when said required discharge oil amount is larger than said maximum dischargeable oil amount.

3. The method of claim 1, wherein said third step comprises the steps of:

(1) comparing a required discharge oil amount of the right-hand side of the pump with a maximum dischargeable oil amount of the right-hand side of the pump; and

(2) setting said required discharge oil amount to be said maximum dischargeable oil amount when said required discharge oil amount is larger then said maximum discharge able oil amount.

4. A method for controlling actuators of hydraulic construction equipment, said actuators supplied with oil from pumps through electrically controllable proportion valves, each pump defined as having left and right hand sides, said method comprising the steps of:

(1) calculating a necessary discharge oil amount required for the moving of actuators moved in a combination way according to a first reference input signal for controlling an oil amount of pumps with a left-hand and right-hand sides, a second reference input signal for controlling a moving speed of said actuators, and maximum dischargeable oil amount signal of said pumps;

(2) determining a sum of necessary oil amounts of said pumps required for the moving of said actuators, and calculating required discharge oil amounts to be supplied to the left-hand side of the pump and the right-hand side of the pump by the same amount respectively;

(3) determining required discharge oil amounts of the left-hand and the right-hand sides of the pumps according to said required discharge oil amounts of said second step and maximum dischargeable oil amounts of the left-hand and the right-hand sides of the pumps;

(4) determining a necessary discharge oil amount required for the moving of said actuators according to a sum of said second step and maximum dischargeable oil amounts of said pumps; and

(5) generating a third reference input signal for controlling the oil amount of said pumps and a fourth reference input signal for controlling the moving speed of said actuators according to said required discharge oil amounts of said fourth step; and

(6) controlling the oil amount of said pumps and the moving speed of said actuators by means of the third and fourth reference input signals generated in said fifth step being applied to said proportion valves.

5. The method of claim 4, wherein said third step comprising the steps of:

(1) comparing the required discharge oil amount of the left-hand side of the pump with the maximum dischargeable oil amount of the left-hand side of the pump;

(2) setting said required discharge oil amount to be said maximum dischargeable oil amount when said required discharge oil amount is larger than said maximum dischargeable oil amount by the comparison of the first step, and adding the difference between said required discharge oil amount and said maximum dischargeable oil amount to the required discharge oil amount of the right-hand side of the pump;

(3) comparing the required discharge oil amount of the right-hand side of the pump with the maximum dischargeable oil amount of the right-hand side of the pump when the required dischage oil amount of the left-hand side of the pump is smaller than the maximum dischargeable oil amount of the left-hand side of the pump; and

(4) setting said required discharge oil amount to be said maximum dischargeable oil amount when said required discharge oil amount is larger than said maximum dischargeable oil amount by the comparison of the third step, and adding the difference between said required discharge oil amount and said maximum dischargeable oil amount to the required discharge oil amount of the left-hand side of the pump.

6. A method for controlling actuators of hydraulic construction equipment, said actuators supplied with oil from pumps through electrically controllable proportion valves, each pump defined as having left and right hand sides, said method comprising the steps of:

(1) calculating a necessary discharge oil amount required for the moving of actuators moved in a combination way according to a first reference input signal for controlling an oil amount of pumps with a left-hand and right-hand sides, a second reference input signal for controlling a moving speed of said actuators, and maximum dischargeable oil amount signal of said pumps;

(2) detecting an adding-up condition of whether or not the oil amounts discharged from said pumps are combined and supplied to any one of said actuators;

(3) determining a sum of necessary oil amounts of said pumps required for the moving of said actuators, and calculating required discharge oil amounts to be supplied to the left-hand side of the pump and the right-hand side of the pump by the same amount respectively;

(4) determining required discharge oil amounts of said pumps according to said required discharge oil amounts of the third step and maximum dischargeable oil amounts of the left-hand side pump and the right-hand side pump;

(5) determining necessary oil amounts required for the moving of said actuators according to the sum of the third step and said maximum dischargeable oil amounts of said pumps;

(6) generating a reference input signal for controlling the oil amount of said pumps and another reference input signal for controlling the moving speed of said actuators according to said required discharge oil amounts of said fifth step;

(7) determining the required discharge oil amount of the left-hand side of the pump to be a sum of necessary oil amount of the left-hand side of the pump when said adding up condition of said second step is not satisfied, and calculating required discharge oil amount of the left-hand side of the pump according to said required discharge oil amount of the left-hand side of the pump and a maximum dischargeable oil amount of the left-hand side of the pump;

(8) determining the required discharge oil amount of the right-hand side of the pump to be a sum of necessary oil amount of the right-hand side of the pump, and calculating required discharge oil amount of the right-hand side of the pump according to said required discharge oil amount of the right-hand side of the pump and a maximum dischargeable oil amount of the right-hand side of the pump;

(9) generating a third reference input signal for controlling the oil amount of said pumps and a fourth reference input signal for controlling the moving speed of said actuators according to said required discharge oil amounts of the seventh and eighth steps; and

(10) controlling the oil amount of said pumps and the moving speed of said actuators by means of the third and fourth input signals generated in said ninth step being applied to said proportion valves.

7. The method of claim 6, wherein said third step comprising the steps of:

(1) comparing the required discharge oil amount of the left-hand side of the pump with the maximum dischargeable oil amount of the left-hand side of the pump;

(2) setting said required discharge oil amount to be said maximum dischargeable oil amount when said required discharge oil amount is larger than said maximum dischargeable oil amount by the comparison of the first step, and adding the difference between said required discharge oil amount and said maximum dischargeable oil amount to the required discharge oil amount of the right-hand side of the pump;

(3) comparing the required discharge oil amount of the right-hand side of the pump with the maximum dischargeable oil amount of the right-hand side of the pump when the required discharge oil amount of the left-hand side of the pump is smaller than the maximum dischargeable oil amount of the left-hand side of the pump; and

(4) setting said required discharge oil amount to be said maximum dischargeable oil amount when said required discharge oil amount is larger than said maximum dischargeable oil amount by the comparison of the third step, and adding the difference between said required discharge oil amount and said maximum dischargeable oil amount to the required discharge oil amount of the left-hand side of the pump.

8. The method of claim 6, wherein said seventh step comprising the steps of:

(1) comparing a required discharge oil amount of the left-hand side of the pump with a maximum dischargeable oil amount of the left-hand side of the pump; and

(2) setting said required discharge oil amount to be said maximum dischargeable oil amount when said required discharge oil amount is larger than said maximum dischargeable oil amount.

9. The method of claim 6, wherein said eightth step comprising the steps of:

(1) comparing a required discharge oil amount of the right-hand side of the pump with a maximum dischargeable oil amount of the right-hand side of the pump; and

(2) setting said required discharge oil amount to be said maximum dischargeable oil amount when said required discharge oil amount is larger then said maximum dischargeable oil amount.

10. An apparatus for controlling actuators of hydraulic construction equipment, comprising:

means for receiving an operation command from an input portion and converting said operation command into an operation signal;

means for calculating a required discharge oil amount of a pump which is proportional to said operation signal and a required moving speed of an actuator which is proportional to the degree of operation and the operation ratio of said operation signal;

means for adjusting said required discharge oil amount and said required moving speed based on a maximum dischargeable oil amount of said pump;

first means for subtracting a real discharge oil amount from said adjusted discharge oil amount and generating a first control signal thereof and second means for subtracting a real moving speed from said adjusted moving speed and generating a second control signal thereof;

first means for controlling the discharge oil amount of said pump according to the first control signal from said first subtracting means; and

second means for controlling the moving speed of said actuator according to the second control signal from said second subtracting means.