Automated system and method for control of movement using parameterized scripts

• US 5,908,458 A
• Filed: 02/06/1997
• Issued: 06/01/1999
• Est. Priority Date: 02/06/1997
• Status: Expired due to Fees

• Current Assignee: Carnegie Mellon University
• Original Assignee: Carnegie Mellon University
• Inventors: Stentz, Anthony J., Rowe, Patrick S.
• Primary Examiner(s): LOUIS JACQUES, JACQUES H
• Application Number:
  US08/796,824
• Time in Patent Office: 845 Days
• Field of Search: 701/50, 701/1, 701/2, 701/23, 701/24, 701/25, 701/27, 172/2, 172/3, 172/4.5, 172/10, 395/86, 395/95, 395/82, 395/85, 395/99, 901/6, 901/2, 901/4, 901/41, 901/42, 318/568.1, 318/568.11, 318/568.16, 318/568.21, 364/189, 364/190, 364/191, 364/193, 37/348, 37/414, 340/685, 340/686, 414/699, 414/730, 414/633
• US Class Current: 701/50
• CPC Class Codes: B25J 9/1658 characterised by programming language
• CPC Class Codes: E02F 3/437 providing automatic sequences of movements, e.g. linear excavation, keeping dipper angle constant
• CPC Class Codes: E02F 9/2041 Automatic repositioning of implements, i.e. memorising determined positions of the implement for dipper-arms or bucket-arms E02F3/434, E02F3/437, E02F3/438, E02F3/439 take precedence
• CPC Class Codes: G05B 2219/35263 Using variables, parameters in program, macro, parametrized instruction

Abstract

Robotic machines, such as mobile manipulators, are controlled by a relatively high-level script while changes in the environment are accommodated by including parameters in the script. Sensors, manual inputs, and other software can be used as sources of data for setting the values of the parameters. The high-level script includes sets of instructions with each set defining movement of one portion of the robotic machine, such as a joint of the manipulator. The several sets of instructions are executed concurrently in a primary script. One or more secondary scripts, each containing concurrently executed sets of instructions may be executed when an abnormal condition is detected. The movements performed by the robotic machine are generally defined by the instructions, but precisely how the movements are performed is determined by the values of the parameters. By using parameterized scripts, it is unnecessary to compute and track trajectories.

Claims

1. A method for controlling complex automated movement by a manipulator, the manipulator having a plurality of links connected at joints and at least one sensor providing perceptual information to software, the software being operable to monitor movement of the manipulator based on the perceptual information and to generate commands for controlling movement of the manipulator, the method comprising:

executing event based pre-stored instructions, including at least one parameter generally defining the complex automated movement, said pre-stored instructions including a primary script formed of concurrently executing scripts;

utilizing the software to determine a value for at least one parameter during the executing of the pre-stored instructions;

obtaining the value for the at least one parameter from any of a sensor input, a data file, and other software;

determining the order to execute the sets of instructions based on the values of the parameters; and

wherein the at least one parameter includes at least one modeled parameter, and wherein the step of utilizing the software includes the steps of executing modeling software to model at least the manipulator during the executing of the pre-stored instructions and providing a value for each modeled parameter.

2. A method, as set forth in claim 1, wherein executing the pre-stored instructions includes the step of concurrently executing sets of instructions for movement of at least two of the links, with a movement of a first link starting during movement of a second link.

3. A method, as set forth in claim 2, wherein determining a value includes the step of obtaining first parameter values indicating when movement of the first link should start depending on an amount of movement of at least the second link.

4. A method, as set forth in claim 3, wherein determining a value includes the step of determining when movement of the first link should start based on when the second link moves a portion of a distance between starting and ending positions.

5. A method, as set forth in claim 4, wherein determining a value includes the step of obtaining second parameter values, different from the first parameter values, indicating when movement of the second link should start depending on an amount of movement of at least the first link.

6. A method, as set forth in claim 1, wherein determining a value includes the step of obtaining a first parameter value representing completion of a first portion of the complex automated movement, and wherein executing pre-stored instructions includes the step of using the first parameter value in controlling a second portion of the complex automated movement.

7. A method, as set forth in claim 6, wherein related mechanisms produce the first and second portions of the complex automated movement, and wherein the step of determining a value obtains the first parameter value by modeling the first and second portions of the complex automated movement.

8. A method, as set forth in claim 1, wherein the pre-stored instructions include at least one secondary script, and wherein determining a value includes the step of evaluating conditions to determine whether to execute the at least one secondary script to control a portion of the complex automated movement.

9. A method for controlling a mobile machine having at least one sensor providing perceptual information to software, the software being operable to monitor movement of the manipulator based on the perceptual information and to generate commands for controlling movement of the manipulator, the method comprising:

storing sets of event based instructions, each set generally defining movement of a corresponding portion of the mobile machine;

utilizing the software to determine values of parameters defining precise movement of the mobile machine;

determining the order to execute the sets of instructions based on the values of the parameters;

repeatedly executing the sets of instructions using the values of the parameters determined prior to each repetition, with at least two of the sets of instructions executed concurrently, and

wherein the parameters include at least one modeled parameter, and wherein determining values includes the step of executing modeling software to model the mobile machine during the executing of the sets of instructions and to provide a value for each modeled parameter.

10. A method, as set forth in claim 9, wherein mechanisms produce the previous and subsequent movements, and wherein the step of determining values obtains a value of the first parameter by modeling the previous and subsequent movements.

11. A method, as set forth in claim 9, wherein the first parameter represents when the subsequent movement should start, and wherein determining values includes the step of obtaining a value of the first parameter based on a second parameter representing when a portion of the previous movement will be completed.

12. A method, as set forth in claim 9, including the step of storing results of modeling the mobile machine, and wherein determining values includes the step of reading the results of the modeling to obtain the values of at least one of the parameters.

13. A method, as set forth in claim 9, wherein the instructions include a primary script, incorporating several sets of the instructions, and at least one secondary script, wherein executing the sets of instructions includes the step of concurrently executing a series of sets of instructions to control a series of movements of the mobile machine, and wherein determining values includes the step of evaluating conditions to determine whether to execute the at least one secondary script to control the series of movements of the mobile machine.

14. A control system for a mobile machine, the mobile machine including a manipulator having a plurality of links and at least one sensor providing perceptual information to software, the software being operable to monitor movement of the manipulator based on the perceptual information and to generate commands for controlling movement of the manipulator comprising:

a storage unit to store sets of instructions, each set generally defining movement of at least one link and to provide memory locations for parameters defining precise movement of the mobile machine;

a processor executing the software, coupled to the storage unit, to determine values of the parameters and to concurrently execute the sets of instructions based on events, the sets of instructions being executed in an order determined by the software, the order being based at least partially on the values of the parameters, and

wherein the storage unit further stores modeling information modeling movement of the mobile machine, and wherein the processor obtains at least one modeled parameter from the modeling information.

15. A control system, as set forth in claim 14, wherein the instructions stored by the storage unit and executed by the processor include at least one timing instruction for starting movement of a first link at a specified time determined by a timing parameter and a previously started movement of a second link.

16. A control system, as set forth in claim 14, wherein the storage unit further stores modeling information, and wherein the processor determines at least one of velocity and acceleration values for at least one parameter, based on at least one of the inputs from the sensors, direction of movement of at least one of the links, position of the manipulator, and the modeling information stored in the storage unit.

17. A mobile manipulator, comprising:

a mobile base;

a manipulator arm mounted on the mobile base and having a plurality of links;

at least one sensor providing perceptual information to software, the software beings operable to monitor movement of the manipulator based on the perceptual information and to generate commands for controlling movement of the manipulator; and

a control system connected to at least the manipulator arm to execute event based pre-stored instructions generally defining automated movement of the mobile manipulator, and to determine values for parameters defining precise movement of the mobile manipulator during execution of the pre-stored instructions, the sets of instruction being executed in an order determined by the software, the order being based at least partially on the values of the parameters, wherein the control system comprises;

a storage unit to store the event based pre-stored instructions generally defining the movement of the mobile manipulator, and to provide memory locations for the parameters defining precise movement of the mobile manipulator; and

a processor coupled to the storage unit and at least the manipulator arm to determine values of the parameters and to execute the pre-stored instructions.

18. A mobile manipulator, as set forth in claim 17, wherein the storage unit further stores modeling information modeling movement of the mobile manipulator, and wherein the processor obtains at least one modeled parameter from the modeling information.

19. A mobile manipulator, as set forth in claim 17, wherein the manipulator arm includes a boom, a stick, and a bucket, moved by corresponding hydraulic cylinders actuated by pumps and valves, and wherein the processor outputs commands to the valves to begin a first movement of the boom and the stick after a second movement of the boom and the stick, based on the values of the parameters.

20. A mobile manipulator, as set forth in claim 19, wherein the control system further comprises sensors coupled to the processor to measure movement of the mobile manipulator, detect conditions surrounding the mobile manipulator, and provide inputs used to determine the parameters.

21. A mobile manipulator, as set forth in claim 17, wherein the pre-stored instructions stored in the storage unit include a primary script and at least one secondary script, and wherein the processor executes the primary script to control a plurality of movements of the mobile manipulator, and evaluates conditions to determine whether to execute the at least one secondary script to control a series of movements of the mobile manipulator."