Features of main control computer for a power machine

• US 20010007087A1
• Filed: 12/27/2000
• Published: 07/05/2001
• Est. Priority Date: 04/23/1999
• Status: Active Grant

• Current Assignee: Clark Equipment Company (Doosan Enerbility Company Limited)
• Original Assignee: Clark Equipment Company (Doosan Enerbility Company Limited)
• Inventors: Rossow, Scott R., Brandt, Kenneth A.
• Granted Patent: US 6,785,596 B2
• Time in Patent Office: Days
• US Class Current: 701/50
• CPC Class Codes: E02F 3/3414 the arms being pivoted at the rear of the vehicle chassis, e.g. skid steer loader
• CPC Class Codes: E02F 3/431 for bucket-arms, front-end loaders, dumpers or the like
• CPC Class Codes: E02F 9/2029 Controlling the position of implements in function of its load, e.g. modifying the attitude of implements in accordance to vehicle speed control for hydraulic or pneumatic drives E02F9/2203, E02F9/2221 and E02F9/2253 take precedence
• CPC Class Codes: E02F 9/2062 Control of propulsion units for control of the prime mover depending on the load in a hydraulic or pneumatic drive E02F9/2246
• CPC Class Codes: E02F 9/2246 Control of prime movers, e.g. depending on the hydraulic load of work tools
• CPC Class Codes: E02F 9/226 Safety arrangements, e.g. hydraulic driven fans, preventing cavitation, leakage, overheating
• CPC Class Codes: E02F 9/2267 Valves or distributors position of valves arrangements on upper-structures E02F9/0875
• CPC Class Codes: E02F 9/2271 Actuators and supports therefor and protection therefor
• CPC Class Codes: E02F 9/24 Safety devices , e.g. for preventing overload E02F9/226 takes precedence
• CPC Class Codes: E02F 9/26 Indicating devices E02F5/145 takes precedence
• CPC Class Codes: F01P 2025/08 Temperature
• CPC Class Codes: F01P 2025/40 Oil temperature
• CPC Class Codes: F01P 7/044 using hydraulic drives
• CPC Class Codes: F02D 2200/023 Temperature of lubricating oil or working fluid
• CPC Class Codes: F02D 41/083 taking into account engine load variation, e.g. air-conditionning
• CPC Class Codes: F15B 21/087 Control strategy, e.g. with block diagram
• CPC Class Codes: Y10T 137/86614 Electric
• CPC Class Codes: Y10T 74/20414 Hydraulic control

Abstract

The present invention is directed to a computer based control system for controlling hydraulic and electromechanical actuators on a power machine, such as a skid steer loader. The computer based control system is configured to implement a number of features to enhance certain operational aspects of the power machine.

Claims

1. A power machine control system for a power machine having an engine, a hydraulic power system providing hydraulic fluid under pressure, and a hydraulic actuator, the control system comprising:

an engine speed sensor for sensing a speed of the engine;

a proportionally controllable valve controllably coupling the hydraulic fluid under pressure to the hydraulic actuator; and

a controller coupled to the engine speed sensor and the valve, providing a modulated control signal to the valve and configured to vary the modulated control signal based on engine speed.

2. The control system of

claim 1

wherein the modulated control signal has a variable duty cycle and wherein the controller is configured to vary the duty cycle based on the sensed engine speed.

3. The control system of

claim 2

wherein the controller includes an associated memory storing a plurality of duty cycle profiles corresponding to a plurality of engine speeds and wherein the controller is configured to access the memory and provide the modulated control signal based on a duty cycle profile accessed in response to the sensed engine speed.

4. A power machine control system for a power machine having an engine, a hydraulic power system providing hydraulic fluid under pressure, and a plurality of hydraulic actuators, the control system comprising:

a plurality of operator inputs each, when actuated, providing an input signal requesting operation of a hydraulic actuator;

a detent request input which, when actuated, provides a signal indicative of a detent request; and

a controller coupled to the plurality of operator inputs and the detent request input and configured to operate a selected one of the plurality of hydraulic actuators in a detent mode when its associated operator input is actuated and the detent request input is substantially simultaneously actuated.

5. The control system of

claim 4

wherein the controller is configured to discontinue operating a hydraulic actuator in detent mode when the detent request input is again subsequently actuated.

6. The control system of

claim 4

wherein the controller is configured to maintain operation of the selected hydraulic actuator in detent mode when an additional one of the plurality of operator inputs is actuated requesting operation of a hydraulic actuator.

7. The control system of

claim 6

wherein, if the hydraulic actuator requested by the additional operator input requires no hydraulic flow conflict with the selected hydraulic actuator, the controller is configured to operate the hydraulic actuator requested by the additional operator input.

8. The control system of

claim 6

wherein, if the hydraulic actuator requested by the additional operator input requires a hydraulic flow conflict with the selected hydraulic actuator, the controller is configured to operate the hydraulic actuator requested by the additional operator input, and discontinue operation of the selected hydraulic actuator.

9. The control system of

claim 8

wherein the controller is configured to again begin operating the selected hydraulic cylinder in detent mode when the additional operator input is no longer actuated.

10. The control system of

claim 4

wherein the controller is configured to operate a predetermined one of the plurality of hydraulic actuators in detent mode when the detent request input is actuated with no other of the plurality of operator inputs actuated.

11. The control system of

claim 4

wherein the controller includes a memory containing a look-up table with associated detent functions and wherein the controller is configured to access the memory based on actuation of the detent request input to determine whether the detent request is possible, and to operate the selected hydraulic actuator based on the determination.

12. A power machine control system for a power machine having an engine, a hydraulic power system providing hydraulic fluid under pressure, and a plurality of hydraulic actuators, and a plurality of controllable electronic devices, the control system comprising:

a plurality of operator inputs each, when actuated, providing an input signal requesting operation of an electronic device; and

a controller coupled to the plurality of operator inputs and providing an energization output to the electronic devices to control the electronic devices based on the operator inputs, the controller further including a diagnostic connection to the electronic devices and being configured to verify operation of the electronic devices based on the diagnostic connection.

13. The power system of

claim 12

wherein one of the operator inputs comprises an ignition input and one of the electronic devices comprises an engine starter, and wherein the controller is configured to sense whether the engine is running and, if not, energize the starter based on actuation of the ignition input and, if so, ignore actuation of the ignition input.

14. A power machine control system for a power machine having an engine, a hydraulic power system providing hydraulic fluid under pressure, and a plurality of actuable valves and associated valve spools, at least one of the valves having an electrically actuable valve spool lock, actuable to move between a locking position and an unlocking position, the control system comprising:

a controller coupled to the valve spool lock and operably providing an energization output to the valve spool lock, the controller controlling the energization output intermittently as a relatively high current output and as a relatively low current output wherein the relatively high current output is higher than the relatively low current output.

15. A power machine control system for a power machine having an engine, a hydraulic power system providing hydraulic fluid under pressure, and at least one lock solenoid, actuable to move between a locking position and an unlocking position, the control system comprising:

a controller coupled to the lock solenoid and operably providing an energization output to move the lock solenoid between the locking and unlocking position, the controller being further configured to determine whether the lock solenoid is controlled by a pull coil and a hold coil or only a single control coil and providing the energization signal based on the determination.

16. The control system of

claim 15

wherein the controller is configured to provide the energization as a pull signal to the pull coil and a hold signal to the hold coil when the lock solenoid is controlled by both the pull coil and the hold coil.

17. The control system of

claim 16

wherein the pull signal energizes the pull coil to move the lock spool between the locking and unlocking positions and wherein the hold signal energizes the hold coil to hold the lock spool in one of the locking and unlocking positions.

18. The control system of

claim 16

wherein the controller is configured to provide the pull signal intermittently as a relatively high current output and as a relatively low current output wherein the relatively high current output is higher than the relatively low current output.

19. The control system of

claim 15

wherein the controller is configured to provide the energization signal to the single control coil when the lock spool is controlled by the single control coil.

20. The control system of

claim 15

wherein the controller is configured to control one or more relays to provide the energization signal.

21. A power machine control system for a power machine having an engine, a traction system coupled to the engine to move the power machine, a hydraulic power system providing hydraulic fluid under pressure, the control system comprising:

a user actuable speed select input providing a speed select signal indicative of a request to operate at a selected one of a plurality of speeds, the speed being determined based on a position of a hydraulic speed valve providing hydraulic fluid under pressure to the traction system;

a controller coupled to the speed select input and providing a modulated output signal to operably control the speed valve to transition from a first position associated with a first speed to a second position associated with the selected speed, based on the speed select signal.

22. The control system of

claim 21

wherein the controller includes associated memory storing a speed modulation profile and wherein the controller is configured to provide the modulated output signal according to the speed modulation profile.

23. The control system of

claim 22

wherein the memory stores a plurality of speed modulation profiles each used by the controller under predetermined operating conditions.

24. The control system of

claim 21

wherein the controller is configured to provide the modulated output signal to control movement of the speed valve from the first to the second position at a first speed during a first portion of the transition and at a second speed during a second portion of the transition.

25. The control system of

claim 24

wherein the first speed is greater than the second speed.

26. The control system of

claim 21

wherein the controller is configured to provide the modulated output signal to control movement of the speed valve from the first to the second position at a substantially constant rate of speed.

27. A power machine control system for a power machine having an engine, a traction system coupled to the engine to move the power machine, and a hydraulic power system providing hydraulic fluid under pressure, the control system comprising:

a sensor sensing one or more operating conditions;

a multi-speed hydraulic oil cooling fan operable at least at a low speed and a high speed; and

a controller operably coupled to the sensor and the cooling fan and configured to control fan speed based on the sensed operating condition.

28. The control system of

claim 27

wherein the sensor comprises:

a hydraulic oil temperature sensor;

an engine coolant temperature sensor; and

an air conditioner status sensor sensing whether an air conditioner is on or off.

29. The control system of

claim 28

wherein the controller is configured to operate the cooling fan at the low speed if the a hydraulic oil temperature is below a threshold temperature, the engine coolant temperature is below a threshold temperature, and the air conditioner is off.

30. A power machine control system for a power machine having an engine, an ignition, a traction system coupled to the engine to move the power machine, a plurality of hydraulic actuators, and a hydraulic power system providing hydraulic fluid under pressure, the control system comprising:

a user input device providing a user input signal indicative of a series of letters or numbers input; and

a controller coupled to the user input device and having associated memory storing at least three levels of passwords, the controller being configured to control different functions of the power machine based on a level of password input.

31. The control system of

claim 30

wherein the controller is configured to accept and implement requested modifications of a normal operation of the power machine if a password having a sufficient predetermined level is input.

32. The control system of

claim 31

and further comprising a speed select input coupled to thew controller providing a speed select input signal indicative of a user input request to select one of a plurality of operating speeds and wherein modification of normal operation comprises changing enablement status of the speed select input.

33. The control system of

claim 32

wherein the controller is configured to change operation of the power machine between the operating speeds according to a transition profile and wherein modification of normal operation comprises changing the transition profile.

34. The control system of

claim 30

wherein the controller is configured to control different functions by accepting an input request to change or disable a lower level password so long as a password having a sufficient predetermined level is received.

35. The control system of

claim 30

wherein the controller is configured to implement a locking feature by locking predetermined functions of the power machine until, upon power-up, a password having a sufficient predetermined level is received, and to control different functions by accepting an input request to disable the locking feature.

36. The control system of

claim 35

wherein the controller is configured to activate a user perceptible indication that the locking feature is disabled, for a predetermined time period upon power-down.

37. The control system of

claim 36

wherein the controller is configured to sense user input of an enable signal and to re-enable the locking feature if the enable signal is received within the predetermined time period.

38. A power machine control system for a power machine having an engine, an ignition, a traction system coupled to the engine to move the power machine, a plurality of hydraulic actuators, and a hydraulic power system providing hydraulic fluid under pressure, the control system comprising:

a first operator input system configured to receive operator inputs and provide input signals indicative of the operator inputs.

a controller coupled to the first operator input system and being configured to sense which type of a plurality of different types of operator input systems it is coupled to and to carry out operations based on the determination.

39. The control system of

claim 38

wherein the controller is configured to sense an identification signal from the first operator input system, the identification signal being indicative of the type of the first operator input system.

40. The control system of

claim 39

wherein the controller is configured to store an indication of the type of the first operator input system once the identification signal is received and, if the first operator input system is replaced by a second operator input system of a different type, to operate with the second operator input system.

41. The control system of

claim 39

wherein the controller is configured to store an indication of the type of the first operator input system once the identification signal is received and, if the first operator input system is replaced by a second operator input system of a different type, to preclude operation with the second operator input system unless a change request sequence has previously been executed with the first operator input system.

42. The control system of

claim 41

wherein the controller is configured to execute the change request sequence by receiving a change request from the first operator input system and receiving sufficient authentication information from the first operator input system.

43. The control system of

claim 42

wherein the sufficient authentication information comprises a password meeting a predetermined one of a plurality of levels.