Industrial Control System with Distributed Motion Planning

• US 20120256566A1
• Filed: 04/10/2012
• Published: 10/11/2012
• Est. Priority Date: 04/11/2011
• Status: Active Grant

• Current Assignee: Rockwell Automation Technologies Incorporated (Allen-Bradley Co., Inc.)
• Original Assignee: Rockwell Automation Technologies Incorporated (Allen-Bradley Co., Inc.)
• Inventors: Chaffee, Mark
• Granted Patent: US 9,323,235 B2
• Time in Patent Office: Days
• US Class Current: 318/34
• CPC Class Codes: G05B 11/01 electric
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G05B 19/042 using digital processors G05B19/05 takes precedence
• CPC Class Codes: G05B 19/0423 Input/output
• CPC Class Codes: G05B 19/0426 Programming the control sequence
• CPC Class Codes: G05B 19/056 Programming the PLC
• CPC Class Codes: G05B 19/4148 characterised by using several processors for different functions, distributed (real-time) systems G05B19/4141 takes precedence
• CPC Class Codes: G05B 2219/1196 Intelligent, smart I-O can function independently, monitoring limit values
• CPC Class Codes: G05B 2219/15074 Modules on bus and direct connection between them for additional logic
• CPC Class Codes: G05B 2219/15078 Modules, construction of system
• CPC Class Codes: G05B 2219/21012 Configurable I-O
• CPC Class Codes: G05B 2219/21021 Intelligent I-O, executes tasks independently from main cpu
• CPC Class Codes: G05B 2219/24015 Monitoring
• CPC Class Codes: G05B 2219/25314 Modular structure, modules
• CPC Class Codes: G05B 2219/25323 Intelligent modules
• CPC Class Codes: G05B 2219/25333 Modules on bus and direct connection between them for additional logic functions
• CPC Class Codes: G05B 2219/33105 Identification of type of connected module, motor, panel
• CPC Class Codes: G05B 2219/33333 Network multiprocessing
• CPC Class Codes: G05B 2219/33338 DNC distributed, decentralised nc, concurrent, multiprocessing
• CPC Class Codes: G05B 2219/34401 Synchronize position controller drive with interpolator
• CPC Class Codes: G05B 23/0205 : by means of a monitoring system capable of detecting and responding to faults
• CPC Class Codes: G06F 13/124 : where hardware is a sequential transfer control unit, e.g. microprocessor, peripheral processor or state-machine

Abstract

An industrial control system provides motion control functions that may distribute motion planning tasks to capable motor drives and motion devices based on stored drive profiles. The profile-aware functions allow control programs to be used with motor drives that are both capable and incapable of executing a motion planning with automatic distribution of the planning tasks as appropriate. Coordination among different devices in the industrial control system when motion planning is distributed may be accommodated through peer-to-peer communication between drives and non-controller devices.

Claims

1. An industrial controller comprising:

a network interface adapted to communicate with one or more connected motor drives;

an electronic computer communicating with the network interface and executing a program stored in non-transient storage medium to;

(1) receive a control program providing motion control instructions;

(2) execute the motion control instructions by;

(a) identifying a motor drive associated with the motor instruction;

(b) determining whether the identified motor drive is capable of executing a motion planner, which provides a time series of motion data for controlling a motor when initiated by a motion command caused by execution of a motion control instruction, and if capable, transmitting the motion command to the identified motor drives over the network interface to the identified drive, otherwise transmitting the motion command to a motion planner in the industrial controller.

2. The industrial controller of claim 1 wherein the control program instructions are executed by calls to functions stored in the industrial controller independent of the control program.

3. The industrial controller of claim 2 wherein the functions and motion planner are stored in firmware in the industrial controller.

4. The industrial controller of claim 3 wherein the network interface is adapted to implement connected messaging between the controller and the motor drives pre-allocating network communication capacity among connections and wherein the electronic computer executes the stored program to open connections between the controller and the drives for communication of motion commands or motion data.

5. The industrial controller of claim 4 wherein the electronic computer executes the stored program to allocate a first portion of the network communication capacity to communication with a motor drive capable of executing a motion planner less than a second portion of the network communication capacity allocated to communicate with a motor drive not capable of executing the motion planner.

6. The industrial controller of claim 5 wherein the first portion of the network communication capacity is periodic a first predefined interval of time and event driven according to triggered by a generation of the motion command and the second portion of the network communication capacity is periodic according to a second predefined interval of time less than the first predefined interval of time.

7. The industrial controller of claim 6 wherein the controller includes a drive profile indicating whether each motor drive includes a motion planner in firmware and then determining whether the identified motor drives capable of executing a motion planner refer to the drive profile.

8. The industrial controller of claim 7 wherein the motion planner sums generated motion profiles from motion commands to provide time series of motion data for controlling a motor being a summation of multiple motion profiles.

9. The industrial controller of claim 8 wherein the motion instructions include instructions for moving a motor between defined positions, instructions for moving a motor at a defined velocity, and instructions for moving a motor in coordination with another motor.

10. The industrial controller of claim 9 wherein the control program is a program generated using a programming language selected from the group consisting of relay ladder logic, structured text, and a sequential function chart.

11. A motor drive comprising:

a switching circuit for synthesizing power voltage to a motor;

a network interface for communicating with an industrial controller;

an electronic computer communicating with the switching circuit and the network interface and executing a program stored in non-transient storage medium to;

(1) receive a motion command from an industrial controller over the network interface, the motion command indicating execution of a motion instruction by the industrial controller;

(2) in response to the motion command, generate time series of motion data for the switching circuit using a motion planner; and

(3) communicate with the industrial controller a completion of a motion profile representing at least a portion of the time series of motion data.

12. The motor drive of claim 11 wherein the motion planner is stored in firmware in the motor drive.

13. The motor drive of claim 12 wherein the network interface is adapted to implement connected messaging between the motor drive and the controller pre-allocating network communication capacity among connections and wherein the electronic computer executes the stored program to receive a connections between the controller and the drive for communication of motion commands or motion data.

14. The motor drive of claim 13 wherein the motion planner sums generated motion profiles from motion commands to provide time series of motion data for controlling a motor being a summation of multiple motion profiles.

15. The motor drive of claim 13 wherein the electronic computer further executes the stored program to implement one-way connected messaging with another device to produce time series of motion data from the motor drive to the other device.

16. The motor drive of claim 15 wherein the other device is selected from the group consisting of:

a controller, another motor drive, and an I/O module.

17. The motor drive of claim 11 wherein the electronic computer further executes the stored program to load and execute instructions from a control program that are not motion instructions.

18. The motor drive of claim 13 wherein the connection is aperiodic to provide a short term data transfer rate as fast as a periodic data transfer rate of the time series of motion and a long term data transfer rate less than the periodic data transfer rate of the time series of motion.

19. An output module comprising:

electrical outputs adapted for connection to external equipment;

a network interface for communicating with other devices;

an electronic computer communicating with the electrical outputs and the network interface and executing a program stored in non-transient storage medium to;

(1) receive over the network interface, motion data providing a time series of data values representing motion of a device;

(2) receive over the network interface a output camming command from an industrial controller over the network interface;

(3) in response to the camming command, generate at an electrical output, cam data providing a time series of data values representing a cycle of desired motion of a device, the cam data based on the received motion data and a cam function held in the output module mapping motion data to cam data; and

(4) send a completion signal to the industrial controller over the network interface after generation of the cycle of cam data.

20. The output module of claim 19 wherein the cam function is stored in firmware in the device.

21. The output module of claim 19 wherein the network interface is adapted to implement connected messaging between the output module and the industrial controller and wherein the electronic computer executes the stored program to open connections between the industrial controller and the output module for communication of motion data and camming commands over the connection.

22. The output module of claim 19 wherein the electronic computer further executes the stored program to load and execute instructions from a portion of a control program.

23. The output module of claim 19 wherein the electronic computer further executes the stored program to implement connected messaging with a non-controller device to share a time series of motion data between the output module and another non-controller device.

24. The output module of claim 23 wherein the non-controller device is selected from the group consisting of:

a motor drive and an I/O module receiving an encoder signal input device.

25. The output module of claim 19 wherein the connection is aperiodic to provide a short term data transfer rate as fast as a periodic data transfer rate of the time series of motion and a long term data transfer rate less than the periodic data transfer rate of the time series of motion

26. An input module comprising:

electrical inputs adapted for connection to external equipment to receive electrical signal therefrom;

a network interface for communicating with other devices;

an electronic computer communicating with the electrical inputs and the network interface and executing a program stored in non-transient storage medium to;

(1) receive over the network interface motion data providing a time series of data value representing motion of the device and a registration command;

(2) in response to a registration command control a recording of motion data based on a predetermined state of an electrical signal from an electrical input;

(4) send a completion signal to the industrial controller over the network interface after completion of recording of motion data together with the recorded motion data.

27. An input module comprising:

electrical inputs adapted for connection to external equipment to receive electrical signal therefrom;

a network interface for communicating with other devices;

an electronic computer communicating with the electrical inputs and the network interface and executing a program stored in non-transient storage medium to;

(1) receive over the network interface motion data providing a time series of data value representing motion of the device and a watch command;

(2) in response to the watch command, control a recording of an electrical signal from an electrical input based on a predetermined state of the motion data;

(4) send a completion signal to the industrial controller over the network interface after completion of recording of electrical signal together with the recorded electrical signal.