Operator assist algorithm for an earth moving machine

Patent metadata

Field	Value
Publication number	US-9896820-B2
Application number	US-201615196092-A
Country	US
Kind code	B2
Filing date	Jun 29, 2016
Priority date	Jun 13, 2014
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

A system and method are provided for assisting a machine operator in controlling a work tool of the machine. In an embodiment, the work tool is set at a first height and the machine is travelling at a first machine speed, resulting in a first work tool or machine load. Based on these factors, a first work tool control mode or second work tool control mode is chosen. In the first work tool control mode, the work tool is manually controlled within a load limit and a work tool height limit, whereas in the second work tool control mode, the work tool load is controlled toward the first work tool load. Based on operator inputs and machine state, as well as other factors such as ground surface, the machine may switch between control modes, or out of automatic work tool control entirely.

First claim

What is claimed is:

1. A machine having an automatic blade control mode for assisting an operator of the machine, the machine comprising
a blade affixed to a chassis, the blade being raisable and lowerable relative to the chassis, and the chassis being propelled overland by one more ground engaging elements;
a blade actuator controlled by a blade controller, the blade controller being configured to execute computer-executable instructions read from a non-transient computer-readable medium, the instructions comprising instructions for:
determining that automatic blade control is desired;
determining a target operating state;
detecting an active operator commanded blade height motion;
detecting that the operator has commanded the blade to a first position and that the machine has a first machine operating state, resulting in a blade load corresponding to a first blade load; and
based on detecting that the commanded blade height motion and that the machine has the first machine operating state, selecting a blade control mode from a first blade control mode and a second blade control mode,
wherein, in the first blade control mode, the blade is manually controlled within a load limit except that the blade is automatically moved to adjust the first machine operating state when an undesirable machine operating state is detected, and
wherein, in the second blade control mode, the blade load is controlled toward the target operating state.

2. The machine in accordance with claim 1 , wherein the selected blade control mode is one of the first blade control mode or the second blade control mode, and
wherein the blade controller is further configured to determine that conditions for the selected one of the first blade control mode and the second blade control mode are no longer met, and to thereafter switch to the other of the first blade control mode and the second blade control mode.

3. The machine in accordance with claim 2 , wherein the selected blade control mode is the first blade control mode, and
wherein the blade controller is further configured to determine that conditions are no longer met by detecting receipt of a manual blade lowering command of greater than a predetermined threshold for longer than a predetermined threshold time, and determining that a speed of the machine is less than a first machine speed threshold.

4. The machine in accordance with claim 2 , wherein the selected blade control mode is the second blade control mode,
wherein the machine operating state includes a machine speed, and
wherein the blade controller is further configured to determine that conditions are no longer met by determining that the machine speed exceeds a second machine speed threshold.

5. The machine in accordance with claim 2 , wherein the selected blade control mode is the second blade control mode, and
wherein the blade controller is further configured to determine that conditions are no longer met by detecting receipt of a manual blade raising command of greater than a predetermined blade raising threshold for longer than a predetermined threshold time.

6. A machine work tool control system comprising:
an operating point determiner configured to determine a target operating state of a machine based on machine data;
an operating point adjuster configured to modify the determined machine operating point to produce a modified machine operating point based on operator input of an operator of the machine;
a controller mode determiner configured to:
determine that automatic blade control is desired,
detect that the operator has commanded the blade to a first position and that the machine has a first machine operating state, resulting in a blade load corresponding to a first blade load,
based on detecting that the commanded blade height motion and that the machine has the first machine operating state, select a blade control mode from a first blade control mode and a second blade control mode,
wherein, in the first blade control mode, the blade is manually controlled within a load limit except that the blade is automatically moved to adjust the first machine operating state when an undesirable machine operating state is detected, and
wherein, in the second blade control mode, the blade load is controlled toward the target operating state

provide a controller mode indicator and a work tool floor value,
the controller mode indicator being indicative of one of the first blade control mode and the second blade control mode, and a work tool floor value; and

a work tool load controller configured to generate machine commands for work tool control assistance based on the modified machine operating point, the controller mode indicator, the work tool floor value and the machine data.

7. The machine work tool control system in accordance with claim 6 , wherein the machine work tool control system is configured for use with a machine having a pitch sensor and having one or more tracks driven by one or more sprockets linked to an engine via a transmission having multiple gears, and wherein the machine data includes one or more of machine ground speed, track speed, sprocket torque, machine pitch, engine speed, or transmission gear.

8. The machine work tool control system in accordance with claim 7 , wherein the machine operates in a material during a cycle and wherein the operating point determiner is further configured to determine the machine operating point by estimating properties of the material and the cycle.

9. A method comprising:
determining, by a blade controller of a machine, that automatic blade control is desired,
the blade controller controlling a blade actuator of the machine;

determining, by the blade controller, a target operating state;
detecting, by the blade controller, an active operator commanded blade height motion;
detecting, by the blade controller, that an operator has commanded a blade of the machine to a first position and that the machine has a first machine operating state, resulting in a blade load corresponding to a first blade load,
the blade being affixed to a chassis of the machine,
the blade being raisable and lowerable relative to the chassis; and

based on detecting the active operator commanded blade height motion and the first machine operating state, selecting, by the blade controller, a blade control mode, selected from a first blade control mode and a second blade control mode,
wherein, in the first blade control mode, the blade is manually controlled within a load limit except that the blade is automatically moved to adjust the first machine operating state when an undesirable machine operating state is detected, and
wherein, in the second blade control mode, the blade load is controlled toward the target operating state.

10. The method in accordance with claim 9 , wherein the selected blade control mode is one of the first blade control mode or the second blade control mode, and
wherein the method further comprises:
determining that conditions for the one of the first blade control mode or the second blade control mode are no longer met; and
switching to another one of the first blade control mode or the second blade control mode.

11. The method in accordance with claim 10 , wherein the selected blade control mode is the first blade control mode, and
wherein the method further comprises:
determining that conditions are no longer met by detecting receipt of a manual blade lowering command of greater than a predetermined threshold for longer than a predetermined threshold time, and
determining that a speed of the machine is less than a speed threshold.

12. The method in accordance with claim 10 ,

Assignees

• Caterpillar Inc

Inventors

• Faivre Joseph L
• Krone Bradley

Classifications

• E02F3/844 Primary

  for positioning the blade, e.g. hydraulically · CPC title

• E02F3/434

  providing automatic sequences of movements, e.g. automatic dumping or loading, automatic return-to-dig · CPC title

• E02F9/265

  with follow-up actions (e.g. control signals sent to actuate the work tool) · CPC title

• E02F9/2029

  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 title

• E02F9/2004

  Control mechanisms, e.g. control levers (control levers per se G05G) · CPC title