Lift vehicle with multiple capacity envelope control system and method
View Patent ↗A multiple envelope control system and method expands the operating capabilities of a lift vehicle. The vehicle includes a platform mounted to a telescoping main boom. The main boom is configured for lift/lower function and telescope function. The multiple envelope control system includes a selector switch for selecting between a plurality of capacity modes including at least a low load mode and a high load mode. A plurality of sensors are strategically positioned on the main boom to cooperatively define position zones of the platform. A control system determines in which position zone the platform located according to signals from the plurality of sensors. The control system controls an envelope of the platform based on a position of the selector switch. By strategically positioning the sensors to define the position zones, inexpensive switches, such as limit switches or the like, can be used, thereby reducing manufacturing costs of the machine.
1. A multiple envelope control system for a lift vehicle, the lift vehicle including a platform mounted to a telescoping main boom, the main boom being configured for lift/lower function and telescope function, the multiple envelope control system comprising:
a selector switch for selecting between a plurality of capacity modes including at least a low load mode and a high load mode;
a plurality of sensors strategically positioned on the main boom, the sensors cooperatively defining position zones of the platform; and
a control system communicating with the selector switch and the plurality of sensors, the control system receiving output from the plurality of sensors to determine in which position zone the platform is located, wherein the control system controls a predefined envelope of the platform based on a position of the selector switch and controls operation of the main boom based on which position zone the platform is located in, and wherein the control system is configured such that when the selector switch is in the high load mode, the control system selectively prevents at least one of the lift/lower function and the telescope function based on which position zone the platform is located in.
2. A multiple envelope control system according to claim 1 , wherein the control system is configured to selectively prevent at least one of the lift/lower function and the telescope function when an angle of the main boom relative to gravity is between +55° and −45°.
3. A multiple envelope control system according to claim 1 , further comprising alarm means for activating an alarm when the platform is placed in a position outside of the envelope.
4. A multiple envelope control system for a lift vehicle, the lift vehicle including a platform mounted to a telescoping main boom, the main boom being configured for lift/lower function and telescope function, the multiple envelope control system comprising:
a selector switch for selecting between a plurality of capacity modes including at least a low load mode and a high load mode;
a plurality of sensors strategically positioned on the main boom, the sensors cooperatively defining position zones of the platform; and
a control system communicating with the selector switch and the plurality of sensors, the control system receiving output from the plurality of sensors to determine in which position zone the platform is located, wherein the control system controls an envelope of the platform based on a position of the selector switch, and wherein the control system is configured such that when the selector switch is in the high load mode, the control system selectively prevents at least one of the lift/lower function and the telescope function based on which position zone the platform is located in,
wherein the position zones defined by the plurality of sensors comprise a plurality of angle regions corresponding to an angle of the main boom relative to gravity and a plurality of length regions corresponding to a telescoped length of the main boom.
5. A multiple envelope control system according to claim 4 , wherein the position zones defined by the plurality of sensors comprise eight angle regions corresponding to the angle of the main boom relative to gravity and four length regions corresponding to the telescoped length of the main boom.
6. A multiple envelope control system according to claim 5 , wherein the control system is configured permit the main boom lift/lower function and telescope function according to the following schedule, where A-D correspond to the four length regions and R 1 -R 8 correspond to the eight angle regions:
Functions
A
B
C
D
Main Lift UP
R1, R2, R3, R4,
R1, R2, R3, R4,
R1, R2, R3, R4,
R1, R2, R3, R4,
R5, R6, R7, R8
R5, R6, R7, R8
R5, R6, R7, R8
R8
Main Lift
R1, R2, R3, R4,
R1, R2, R3, R4,
R1, R2, R3, R4,
R1, R5, R6, R7,
Down
R5, R6, R7, R8
R5, R6, R7, R8
R5, R6, R7, R8
R8
Main Tele Out
R1, R2, R3, R4,
R1, R2, R3, R4,
R1, R2, R7, R8
R1, R2, R7, R8
R5, R6, R7, R8
R5, R6, R7, R8
Main Tele In
R1, R2, R3, R4,
R1, R2, R3, R4,
R1, R2, R3, R4,
R1, R2, R3, R6,
R5, R6, R7, R8
R5, R6, R7, R8
R5, R6, R7, R8
R7, R8.
7. A multiple envelope control system according to claim 1 , wherein the plurality of sensors comprise limit switches.
8. A multiple envelope control system according to claim 7 , wherein the position zones defined by the plurality of sensors comprise a plurality of length regions corresponding to a telescoped length of the main boom, and wherein the limit switches comprise first and second multiple capacity switches and first and second main transport switches, the control system being configured to respectively use opposite cam logic with the multiple capacity switches and the main transport switches to determine in which length region the platform is located.
9. A multiple envelope control system according to claim 8 , wherein the position zones defined by the plurality of sensors comprise four length regions (A, B, C, D) corresponding to a telescoped length of the main boom, the control system determining which length region the platform is located in according to the following schedule:
Switch States/Boom Length Regions
Multiple Cap. Switch #1
Off Cam
Off Cam
Off Cam
Disagree
On Cam
On Cam
On Cam
Disagree
Disagree
Multiple Cap. Switch #2
On Cam
On Cam
On Cam
Disagree
Off Cam
Off Cam
Off Cam
Disagree
Disagree
Control System Conclusion of
B/A
B/A
B/A
Disagree
C/D
C/D
C/D
Disagree
Disagree
Multiple Cap Switches
Main Transport Switch #1
Off Cam
Disagree
On Cam
On Cam
On Cam
Disagree
Off Cam
Off Cam
Disagree
Main Transport Switch #2
On Cam
Disagree
Off Cam
Off Cam
Off Cam
Disagree
On Cam
On Cam
Disagree
Control System Conclusion of
A/D
Disagree
B/C
B/C
B/C
Disagree
A/D
A/D
Disagree
Main Transport Switches
Control System Conclusion of
A
A/B
B
B/C
C
C/D
D
Switch
Switch
Main Boom Length
Fault
Fault.
10. A multiple envelope control system for a lift vehicle, the lift vehicle including a platform mounted to a telescoping main boom, the main boom being configured for lift/lower function and telescope function, the multiple envelope control system comprising:
a selector switch for selecting between a plurality of capacity modes including at least a low load mode and a high load mode;
a plurality of sensors strategically positioned on the main boom, the sensors cooperatively defining position zones of the platform; and
a control system communicating with the selector switch and the plurality of sensors, the control system receiving output from the plurality of sensors to determine in which position zone the platform is located, wherein the control system controls a predefined envelope of the platform based on a position of the selector switch and controls operation of the main boom based on which position zone the platform is located in, and wherein the control system controls a position of the selector switch according to a sensed load on the platform.
11. A lift vehicle comprising:
a vehicle base;
a tower boom pivotally coupled at one end to the vehicle base;
a telescoping main boom pivotally coupled to the tower boom at an opposite end thereof;
a platform mounted to the telescoping main boom, the telescoping main boom being configured for lift/lower function and telescope function; and
a multiple envelope control system including:
a selector switch for selecting between a plurality of capacity modes including at least a low load mode and a high load mode,
a plurality of sensors strategically positioned on the main boom, the sensors cooperatively defining position zones of the platform, and
a control system communicating with the selector switch and the plurality of sensors, the control system receiving output from the plurality of sensors to determine in which position zone the platform is located, wherein the control system controls a predefined envelope of the platform based on a position of the selector switch and controls operation of the main boom based on which position zone the platform is located in, and wherein the control system is configured such that when the selector switch is in the high load mode, the control system selectively prevents at least one of the lift/lower function and the telescope function based on which position zone the platform is located in.