Control method for controlling an excavator and excavator comprising a control unit implementing such a control method

• US 10,458,095 B2
• Filed: 01/07/2015
• Issued: 10/29/2019
• Est. Priority Date: 01/07/2015
• Status: Active Grant

• Current Assignee: Volvo Construction Equipment AB (Volvo AB)
• Original Assignee: Volvo Construction Equipment AB (Volvo AB)
• Inventors: Caillieret, Roger, Savoye, Francois, Nedjimi, Ahcene, Bruyere, Lilian
• Primary Examiner(s): Sarwar, Babar
• Application Number:
  US15/540,066
• Publication Number:
  US 20170356157A1
• Time in Patent Office: 1,756 Days
• CPC Class Codes: E02F 3/42 Drives for dippers, buckets, dipper-arms or bucket-arms
• CPC Class Codes: E02F 3/43 Control of dipper or bucket position; Control of sequence of drive operations
• CPC Class Codes: E02F 9/2079 Control of mechanical transmission for hydrostatic transmission or hydraulic torque converter E02F9/2253
• CPC Class Codes: E02F 9/2083 Control of vehicle braking systems
• CPC Class Codes: E02F 9/2095 Control of electric, electro-mechanical or mechanical equipment not otherwise provided for, e.g. ventilators, electro-driven fans control of hydraulic driven equipment E02F9/22

Abstract

A control method includes the steps of: providing an excavator including: several movable members configured to move parts of the excavator, one actuating set comprising several actuators, among which at least one electric actuator, one or more static brakes movable between: i) a locking position and ii) an unlocking position, a command device to receive commands from an operator, a control unit to control the actuators and the static brakes based on command signals. The control method further includes: a reception step for receiving a command signal, an actuation check step to check whether the command signal requires the control unit to actuate an actuator of the actuating set, and if yes, an unlocking step wherein the control unit releases the static brakes of the actuating set.

Claims

1. A control method, for controlling an excavator, the control method including a step of:

providing an excavator including at least;

several movable members, each movable member being configured to move at least a part of the excavator,

at least one actuating set comprising at least two actuators, the at least two actuators including at least one electric actuator, each actuator being configured to actuate at least one of the movable members,

at least one static brake movable between;

i) a locking position where the at least one static brake locks the at least one electric actuator, and ii) an unlocking position where the at least one static brake unlocks the at least one electric actuator,

a command device configured to receive commands from an operator and to generate command signals based on the commands,

a control unit configured to receive the command signals and to control the actuators and the at least one static brake based on the command signals,

the control method further including at least;

a reception step wherein the control unit receives a command signal,

an actuation check step wherein the control unit checks whether the command signal requires the control unit to actuate at least one actuator belonging to the at least one actuating set, and

an unlocking step, after the command signal requires the control unit to actuate an actuator belonging to the at least one actuating set, wherein the control unit controls the at least one static brake so that the at least one static brake moves towards its unlocking position.

2. The control method according to claim 1, wherein the control unit controls the at least one static brake so that the at least one static brake moves towards its unlocking position within less than 500 millisecond.

3. The control method according to claim 1, wherein the at least one actuating set comprises at least two electric actuators, wherein the excavator includes at least two static brakes, each static brake being movable between:

i) a respective locking position where the static brake locks a respective electric actuator, and ii) a respective unlocking position where the static brake unlocks the respective electric actuator, and wherein, during the unlocking step, the control unit controls each static brake so that each static brake moves towards its respective unlocking position.

4. The control method according to claim 3, wherein the at least two electric actuators each includes a respective electric motor, and wherein, during the unlocking step, the control unit energizes:

at least one electric motor so as to actuate at least one of the electric actuators, and

the remaining electric motors of all of the electric actuators belonging to the at least one actuating set in order to maintain in a static position the electric actuators.

5. The control method according to claim 4, wherein, during the unlocking step, the control unit energizes all the electric motors so as to actuate all of the electric actuators belonging to the at least one actuating set.

6. The control method according to claim 1, wherein the actuators belonging to the at least one actuating set are configured to cooperate in order to generate a combined motion of at least one of the movable members.

7. The control method according to claim 6, further including an actuation step wherein the control unit actuates at least two actuators belonging to the at least one actuating set when the command signal requires the control unit to actuate the at least two actuators belonging to the at least one actuating set.

8. The control method according to claim 1, wherein the at least one electric actuator is selected in the group consisting of a linear electric actuator and a rotational electric actuator.

9. The control method according to claim 1, wherein the at least one electric actuator includes a respective electric motor, and wherein, during the unlocking step, the control unit energizes the electric motor.

10. The control method according to claim 9, wherein, during the unlocking step, the control unit energizes the electric motor of the at least one electric actuator before the at least one static brake moves towards its respective unlocking position.

11. The control method according to claim 9, wherein, during the unlocking step, the control unit energizes the electric motor of the electric actuator substantially during a period where the at least one static brake moves towards its respective unlocking position.

12. The control method according to claim 11, wherein, during the unlocking step, the control unit energizes the electric motor of the at least one electric actuator progressively as the at least one static brake moves towards its respective unlocking position.

13. The control method according to claim 9, wherein, during the unlocking step, the control unit energizes the electric motor so as to actuate the at least one electric actuator belonging to the at least one actuating set.

14. The control method according to claim 9, wherein, during the unlocking step, the control unit energizes the at least one electric motor so as to maintain in a static position the at least one electric actuator.

15. The control method according to claim 1, wherein the control unit comprises a memory for storing at least a dataset containing data identifying each actuator belonging to the at least one actuating set.

16. The control method according to claim 1, further comprising a cab, wherein each one of the movable members is selected from the group consisting of a tool configured to work on a site, an arm configured to move the tool, a boom configured to move the arm, an offset member configured to offset the boom, a drive member configured to displace the cab with respect to a site ground and a blade configured to partially lift the cab.

17. The control method according to claim 16, wherein the movable members include a tool configured to work on a site and an arm configured to move the tool,

wherein the at least one actuating set comprises a tool actuating set, the tool actuating set including at least a tool actuator configured to drive the tool and an arm actuator configured to drive the arm, and

wherein the at least one static brake includes at least a tool static brake configured to lock the tool actuator and an arm static brake configured to lock the arm actuator.

18. The control method according to claim 17, wherein the movable members further include a boom configured to move the arm,

wherein the tool actuating set further includes a boom actuator configured to drive the boom, and

wherein the static brakes further include a boom static brake configured to lock the boom actuator.

19. The control method according to claim 18, wherein the movable members further include an offset member configured to offset the boom, and wherein the tool actuating set further includes an offset actuator configured to drive the offset member, and wherein the static brakes further include an offset static brake configured to lock the offset actuator.

20. The control method according to claim 1, further comprising a cab, wherein the movable members further include a blade configured to partially lift the cab and a drive member configured to displace the cab,

wherein the at least one actuating set comprises a cab actuating set, the cab actuating set including at least a blade actuator configured to drive the blade and a drive actuator configured to drive the drive member, and

wherein the at least one static brake includes at least a blade static brake configured to lock the blade actuator and a drive static brake configured to lock the drive member.

21. The control method according to claim 20, wherein the drive member comprises at least two drive devices including a right track drive device configured to impart a translation to a right part of the excavator and a left track drive device configured to impart a translation to a left part of the excavator, and wherein the cab actuating set is configured to actuate both the right track drive device and the left track drive device.

22. The control method according to claim 20, wherein the movable members further include a swing member configured to swing the cab, wherein the cab actuating set further includes at least a swing actuator configured to drive the swing member, and wherein the static brakes include at least a swing static brake configured to lock the swing actuator.

23. The control method according to claim 1, further including a lock check step wherein the control unit checks whether the at least one electric actuator is currently locked,

wherein the control unit performs the unlocking step in case the at least one electric actuator is currently locked.

24. The control method according to claim 1, wherein the excavator further includes several position sensors, each position sensor being configured to detect the position of a respective electric actuator and to send position signals to the control unit, the control unit being further configured to determine the position of each one of the electric actuators based upon the position signals.

25. The control method according to claim 24, wherein each position sensor is an encoder coupled with an electric actuator.

26. The control method according to claim 1, wherein the control unit further comprises at least one timer (58) for counting at least one predetermined period as from the start of the reception step, and wherein, after the predetermined period has elapsed without the control unit receiving any further command signal, the control unit controls the at least one static brake so as to move the at least one static brake towards its respective locking position.

27. The control method according to claim 1, wherein the excavator further comprises at least one temperature sensor configured to measure the temperature of the at least one electric actuator and connected to the control unit, the control method further including a cooling step wherein, in case the temperature exceeds a predetermined temperature threshold, the control unit controls the at least one static brake so as to move the at least one static brake towards its respective locking position.

28. The control method according to claim 1, wherein the at least one electric actuator includes a respective electric motor, and wherein, during the locking step, the static brake prevents rotation of the electric motor.

29. An excavator including at least:

several movable members, each movable member being configured to move at least a part of the excavator,

at least one actuating set comprising at least two actuators, the at least two actuators including at least one electric actuator configured to actuate at least one of the movable members,

at least one static brake movable between;

i) a locking position where the at least one static brake locks the at least one electric actuator, and ii) an unlocking position where the at least one static brake unlocks the at least one electric actuator,

a command device configured to receive commands from an operator and to generate command signals based on the commands,

a control unit configured to receive the command signals and to control the actuators and the at least one static brake based on the command signals, the control unit being further configured to perform at least;

a reception step wherein the control unit receives a command signal,

an actuation check step wherein the control unit checks whether the command signal requires the control unit to actuate an actuator belonging to the at least one actuating set, and

an unlocking step, after the command signal requires the control unit to actuate an electric actuator belonging to the at least one actuating set, wherein the control unit controls the at least one static brake so that the at least one static brake moves towards its unlocking position.

30. The excavator according to claim 29, wherein the at least one electric actuator includes a respective electric motor, and wherein, during the locking step, the static brake prevents rotation of the electric motor.