CN105692456A

CN105692456A - Load moment control system based on CAN bus

Info

Publication number: CN105692456A
Application number: CN201410698588.2A
Authority: CN
Inventors: 张宗发
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-11-28
Filing date: 2014-11-28
Publication date: 2016-06-22

Abstract

A load moment control system based on a CAN bus provided by the invention includes an industrial personal computer, also includes an interface card. The interface card is connected between a data bus and the industrial personal computer; the data bus is connected to a data acquisition module and a relay output module; the relay output module is connected to a crane control; and the data acquisition module acquires a load moment signal. The load moment control system based on the CAN bus realizes load moment remote monitoring based on CAN bus and SNMP protocol, and can ensure reliable and real-time remote data transmission and command execution and ensure the safe operation of the crane.

Description

Hoisting moment based on CAN controls system

Technical field

The present invention relates to areas of information technology, specifically refer to control system based on the hoisting moment of CAN。

Background technologyIn the control system of engineering machinery, computer technology, network communications technology application increasingly extensive。CAN transmits high reliability and high real-time due to its data, has become as the fact that industrial field data transmission means one of standard, has now been widely used in the data communication of the industry-by-industries such as automobile, Industry Control, intelligent building, coal mine equipment。CAN adopts short frame message structure, and real-time is good, and has perfect data check, fault processing and error-detection mechanism, and CAN node can automatically disengage bus under gross error in addition, and bus communication is not affected。In CAN network, data transmit-receive, hardware error detection complete by CAN controller hardware, greatly strengthen the anti-electromagnetic interference capability of CAN network。

SNMP as a sub-protocol of TCP/IP protocol suite, is one of network management solution of proposing of IEITF research group, and it obtains a wide range of applications in industrial quarters as a kind of succinct and popular NMP。Important component part in SNMP network management model includes: NMP, management end (Manager), agency (Agent) and management information bank (MIB)。The basic thought of its management is, by cooperating with each other between management end and agency, performs network management activities [2] in a distributed fashion。Management end is responsible in network various resources and equipment, adopts poll (polling) or manual mode to send Get(to long-range agency and reads) and Set(arrange) request command, to obtain information or to implement control。Agency resides on equipment, is responsible for actual management and the control of equipment, the administration order of response and execution management end, and returns response message。MIB deposits all information of managed object resource, and management end is by acting on behalf of the variate-value reading and arranging in mib file, to realize the monitoring to managed devices。MIB on each network equipment is responsible for maintenance by agency again。Advantage maximum for SNMP is that agreement is succinct, and extensibility is strong, as long as being loaded in by new MIB on management software just can realize the control to new terminal and access。

Hoisting moment restriction system is safety convenience instrument important during hoisting machinery runs, and its core is in that the degree of accuracy that compulsory exercise is performed, and this not only depends on the precision of sensor and executor, also depends on the execution speed of data acquisition signal and order。The left-right rotation angle signal of such as lifting lever, by data acquisition module by signal normalization, compares with parameter set in advance after master control industrial computer receives this signal, and turns left or right-hand rotation switch motion according to deviation commander, and finally puts in place。Traditional hoisting moment controls system and adopts the signal based on RS485 to transmit, and its communication baud rate is only 57.6Kbps, and system stability is poor, and motor is properly functioning with other powerful devices usually influential system。

Summary of the invention

For the defect overcoming prior art to exist, the invention discloses a kind of hoisting moment based on CAN and control system。

Hoisting moment based on CAN of the present invention controls system, including industrial computer, also include interface card, described interface card is connected between data/address bus and industrial computer, described data/address bus is connected with data acquisition module and relay output module, described relay output module is connected with crane control, and described data collecting module collected hoisting moment signal, described data/address bus is CAN。

Preferably, described hoisting moment signal includes the angle signal of lifting power arm, length signals and pressure signal。

Preferably, described data acquisition module is ICAN4017。

Preferably, described relay output module is ICAN2404。

Hoisting moment control system based on CAN of the present invention achieves the hoisting moment based on CAN and snmp protocol and remotely monitors, it is possible to ensure that reliable, real-time remote data transmission and order perform, it is ensured that the safe operation of hoisting machinery。

Accompanying drawing explanation

Accompanying drawing described herein is used for providing being further appreciated by the embodiment of the present invention, constitutes the part of the application, is not intended that the restriction to the embodiment of the present invention。In the accompanying drawings:

Fig. 1 is one detailed description of the invention schematic diagram of the present invention。

Detailed description of the invention

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in further detail。

The signals such as the angle of on-the-spot crane work, length, pressure are gathered by various kinds of sensors, input iCAN data acquisition module, pass to on-the-spot industrial computer through CAN, and be stored in the mib file in resident industrial computer, for operating in the management end software query calls remotely monitoring in computer。Meanwhile, the state variable of each switch also is stored in this mib file, is altered to new value according to the value that arranges that management end is sent, then through by Field Bus CAN network delivery to output control module to control the state of each switch, reach the purpose that hoisting moment is remotely monitored。System structure is as shown in Figure 1。

Wherein, iCAN-4017AI functional module has 8 analog input channels, tunnel, meet CAN2.0B protocol specification, for gathering the input signal of sensor, will input signal after variable connector, AD conversion through light-coupled isolation module, by CAN communication to the analog signals of input sent on-the-spot industrial computer。ICAN-2404 relay functional modules has 4 tunnels to have the relay output channel of self-retaining function, it is operationally, industrial computer sends the Control data of output to this module by CAN, module drives relay by output after Phototube Coupling, it is achieved the control to the switch that rises, declines, turns left, turns right。

The software of system is broadly divided into two parts, and the first is in order to extract and arrange the data in CANbus fieldbus, and it two is based on snmp protocol and realizes the telecommunication of data。

In order to sensing data is processed, real-time acquisition system duty, and each executor is controlled accordingly, the function library that we utilize iCAN module subsidiary has been write corresponding program under VC++ development platform and to be gathered by each iCAN module the signal of sensor, controls the state of each switch。ICAN main website function library provides with the form of dynamic link library (DLL), enclosed inside iCAN agreement, and shielding accesses and controls details, it is provided that the interface [3] that fieldbus iCAN equipment in network is accessed。By calling this function library, it is possible to make PC-CAN main website card and iCAN slave station module carry out communication, complete the information exchange between each node device on industrial computer and fieldbus。

In order to communicate between remotely monitoring computer and on-the-spot industrial computer based on snmp protocol, it is necessary to develop two-part program, i.e. management end program and Agent。Management end program operates in remotely to be monitored in computer, Agent resides on the industrial computer being connected with Field Bus CAN, also includes management information bank MIB, MIB and store the information of managed object in agency, including angle, pressure data, the open and-shut mode etc. of each switch。Management end sends Get(with polling mode to long-range agency and reads) and Set(setting) request command, to obtain angle, length and pressure information or to implement on-off control。Act on behalf of and the content according to request is extracted information needed from local MIB, and in response message mode, result is passed back to management end。Specifically, it constantly checks the state of this locality on the one hand, updates the variate-value in MIB storehouse；On the other hand, the request message of management end is intercepted in circulation, and makes corresponding response, reads or revises the variate-value in MIB, returning result to management end。

Management end sends Get request to agency, it is desirable to the data such as returning pressure, angle。After agency accepts request, PDU is carried out dissection process, and call corresponding sub-function module, the value of the variablees such as " pressure ", " angle ", " length " is read from mib file, these data are packaged into corresponding PDU and are sent to management end as the response to Get request by then proxy call coding module。After management end receives corresponding data, they are made comparisons with reference value set in advance, according to the deviation between actual value and setting value, it is judged that whether hoisting moment exceedes restriction, and sends corresponding on-off control order accordingly。

The principle of Set request is similar with Get, but is write a certain new value to corresponding variable, rather than reads, thus realizing the control to managed devices。Within the system, management end sends Set request to agency, to arrange the state variable of each switch。After agency accepts request, the new value of each " switch " variable of write in mib file, and by on-the-spot CAN pass to output control module control to rise, decline, turn left, the action switched of turning right。

MIB is the data base about being managed destination object, and its data structure is tree-like。Mib file in native system stores the various signals of spot sensor collection and the state of switch, and by reading and arrange the value of these mib objects, management end completes monitoring and controls。Mib file is write the middle most important point and is determined that the variable to define。

AdventNetAgentToolkitCEdition tool kit is adopted to carry out development and agency program, this tool kit provides an extensive and complete development environment, and a series of Agent Development instrument such as editing machine, compiler and testing tool is defined with proxy information, reduce the complexity of Agent Development。The agency developed only takes up minimum space, but has higher performance, and the extension acted on behalf of has influence on the performance of application and equipment hardly。After writing mib file, Agent is write according to the development process of AgentToolkitCEdition instrument, its major function is that mib file is managed, and realize intercepting the network port, the decoding of SNMP datagram and coding, the request of management end is processed, and the management to hardware。

Utilize NET-SNMP kit to write management end program under VC++.NET development platform。NET-SNMP kit is presently the most one of popular snmp protocol kit based on C++, snmp protocol module in kit is that user uses snmp protocol to provide the basis of good protocol to build network management-application layer software, it provides a series of api function and is available for developer's use。The management end program of native system operates in remotely to be monitored on computer, and carries out remote data communication between agency resident on the industrial computer of working site, mainly completes Get and Set and operates two tasks。

Above-described detailed description of the invention; the purpose of the present invention, technical scheme and beneficial effect have been further described; it is it should be understood that; the foregoing is only the specific embodiment of the present invention; the protection domain being not intended to limit the present invention; all within the spirit and principles in the present invention, any amendment of making, equivalent replacement, improvement etc., should be included within protection scope of the present invention。

Claims

1. control system based on the hoisting moment of CAN, including industrial computer, it is characterized in that, also include interface card, described interface card is connected between data/address bus and industrial computer, and described data/address bus is connected with data acquisition module and relay output module, and described relay output module is connected with crane control, described data collecting module collected hoisting moment signal, described data/address bus is CAN。

2. the hoisting moment based on CAN according to claim 1 controls system, it is characterised in that described hoisting moment signal includes the angle signal of lifting power arm, length signals and pressure signal。

3. the hoisting moment based on CAN according to claim 1 controls system, it is characterised in that described data acquisition module is ICAN4017。

4. the hoisting moment based on CAN according to claim 1 controls system, it is characterised in that described relay output module is ICAN2404。