Robot controlling device

• US 8,744,625 B2
• Filed: 10/07/2011
• Issued: 06/03/2014
• Est. Priority Date: 11/05/2010
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Negishi, Mahito
• Primary Examiner(s): Black, Thomas
• Assistant Examiner(s): LOUIE, WAE LENNY
• Application Number:
  US13/269,215
• Publication Number:
  US 20120116582A1
• Time in Patent Office: 970 Days
• Field of Search: 700/245, 700/254, 900/1, 900/2
• US Class Current: 700/245
• CPC Class Codes: B25J 9/161 Hardware, e.g. neural networks, fuzzy logic, interfaces, processor
• CPC Class Codes: B25J 9/1656 characterised by programming, planning systems for manipulators
• CPC Class Codes: B25J 9/1664 characterised by motion, path, trajectory planning
• CPC Class Codes: G05B 2219/33081 Parallel computing, pipeline
• CPC Class Codes: G05B 2219/40449 Continuous, smooth robot motion
• CPC Class Codes: G05B 2219/40495 Inverse kinematics model controls trajectory planning and servo system
• CPC Class Codes: G05B 2219/40512 Real time path planning, trajectory generation

Abstract

In the control of a multi-joint robot main body, it is necessary to execute intricate track calculations and synchronous operations in parallel, even if the track calculations are intricate and times required for the calculations are indefinite. For this purpose, a robot controlling device of the present invention includes a shared memory, and first and second processing units connected to the shared memory. The first processing unit performs track calculation processing which includes calculating operation command data indicating a series of command values to be output to arm motors, based on a command to operate the multi-joint robot main body to a desired position posture, and storing the calculated operation command data in the shared memory. The second processing unit performs synchronous processing which includes acquiring the operation command data stored in the shared memory, and synchronously outputting the command values to the arm motors at predetermined time intervals.

Claims

1. A robot controlling device which outputs a command value of a joint angle to each of a plurality of driving units which drive joints of a multi joint robot main body, to control driving operations of the respective driving units, the robot controlling device comprising:

a shared memory; and

a first processing unit and a second processing unit accessibly connected to the shared memory,

wherein the first processing unit performs track calculation processing which includes calculating operation command data indicating a series of command values to be output to the respective driving units, on the basis of a command to operate the multi-joint robot main body to a desired position posture, and storing the operation command data as calculation results in the shared memory; and

the second processing unit performs synchronous processing which includes acquiring the operation command data stored in the shared memory, and synchronously outputting the command values to the respective driving units at predetermined time intervals,

wherein the shared memory stores commands each including;

an operation describing portion where the command to operate the multi-joint robot main body to the desired position posture is described;

a calculation start condition describing portion where calculation start conditions to calculate the operation command data on the basis of the command described in the operation describing portion are described; and

an operation start condition describing portion where operation start conditions to operate the respective driving units are described,

wherein the first processing unit comprises;

a calculation start condition determining unit which refers to the calculation start condition describing portion of each of the commands stored in the shared memory and acquires, from the shared memory, the command described in the operation describing portion of the command satisfying the calculation start conditions; and

a calculating unit which calculates the operation command data on the basis of the command acquired by the calculation start condition determining unit, to store the operation command data in the shared memory;

wherein the second processing unit comprises;

an operation start condition determining unit which refers to the operation start condition describing portion of each of the commands stored in the shared memory and acquires, from the shared memory, the operation command data corresponding to the command satisfying the operation start conditions among pieces of the operation command data stored in the shared memory; and

a transmitting unit which acquires the command value corresponding to each of the driving units from the operation command data acquired by the operation start condition determining unit, to synchronously output the command values to the respective driving units at predetermined time intervals.

2. The robot controlling device according to claim 1, wherein the second processing unit comprises:

a buffer unit including tracks corresponding to the driving units, respectively;

a buffer writing unit which continuously writes the command values of the operation command data acquired by the operation start condition determining unit in the track corresponding to each of the driving units in order of time series; and

a buffer reading unit which reads the command values to be output at the same time from the respective tracks of the buffer unit.

3. The robot controlling device according to claim 1, wherein the calculating unit omits the calculation in a case where it is determined that the operation command data calculated on the basis of the command acquired by the calculation start condition determining unit matches the operation command data stored in the shared memory.

4. The robot controlling device according to claim 3, wherein the operation start condition determining unit calculates a difference between the last command value of the operation command data previously acquired from the shared memory and the first command value of the operation command data presently acquired from the shared memory, and adds an offset value which gradually decreases from the difference as an initial value to zero, to the command value in order of time series from the first command value of the operation command data presently acquired from the shared memory, to correct the command value.

5. The robot controlling device according to claim 1, wherein the second processing unit comprises a robot state monitoring unit which monitors the posture of the multi joint robot main body,

the calculating unit calculates the operation command data by use of an inverse kinematic model, and

the robot state monitoring unit calculates the position posture of the multi-joint robot main body by use of a forward kinematic model.

6. The robot controlling device according to claim 1, further comprising:

a sensor which detects the state of the multi joint robot main body,

wherein the second processing unit comprises a command value correcting unit which corrects the command value of the operation command data acquired by the operation start condition determining unit, by use of the detection result of the sensor.

7. A robot controlling device which outputs a command value of a joint angle to each of a plurality of driving units which drive joints of a multi joint robot main body, to control driving operations of the respective driving units, the robot controlling device comprising:

a shared memory; and

a first processing unit and a second processing unit accessibly connected to the shared memory,

wherein the first processing unit performs track calculation processing which includes calculating operation command data indicating a series of command values to be output to the respective driving units, on the basis of a command to operate the multi-joint robot main body to a desired position posture, and storing the operation command data as calculation results in the shared memory; and

the second processing unit performs synchronous processing which includes acquiring the operation command data stored in the shared memory, and synchronously outputting the command values to the respective driving units at predetermined time intervals,

wherein the shared memory stores commands each including;

an operation describing portion where the command to operate the multi-joint robot main body to the desired position posture is described;

a calculation start condition describing portion where calculation start conditions to calculate the operation command data on the basis of the command described in the operation describing portion are described;

an operation start condition describing portion where operation start conditions to operate the respective driving units are described; and

a state variable which indicates at least one of a calculation start waiting state, a calculating state, a calculation completing state and an operating state,

wherein the first processing unit comprises;

a calculation start condition determining unit which refers to the calculation start condition describing portion of each of the commands stored in the shared memory and acquires, from the shared memory, the command described in the operation describing portion of the command satisfying the calculation start conditions and having the state variable indicating the calculation start waiting state;

a first state variable changing unit which changes, to the calculating state, the state variable of the command acquired from the commands stored in the shared memory by the calculation start condition determining unit;

a calculating unit which calculates the operation command data on the basis of the command acquired by the calculation start condition determining unit, to store the operation command data in the shared memory; and

a second state variable changing unit which changes, to the calculation completing state, the state variable of the command corresponding to the operation command data completed to be calculated by the calculating unit among the commands stored in the shared memory,

wherein the second processing unit comprises;

an operation start condition determining unit which refers to the operation start condition describing portion of each of the commands stored in the shared memory and acquires, from the shared memory, the operation command data corresponding to the command satisfying the operation start conditions and having the state variable indicating the calculation completing state among the pieces of operation command data stored in the shared memory;

a third state variable changing unit which changes, to the operating state, the state variable of the command corresponding to the operation command data acquired from the commands stored in the shared memory by the operation start condition determining unit; and

a transmitting unit which acquires the command value corresponding to each of the driving units from the operation command data acquired by the operation start condition determining unit, to synchronously output the command values to the respective driving units at predetermined time intervals.