Summary of the invention
The present invention is directed to the resource-constrained problem of fieldbus in track traffic, propose to simplify sampled signal by slip and solve the resource-constrained problem of multiloop network control system, and the step-length proposing by adopting dynamic change slip to simplify device realizes the strategy that the bus system in the multi-control loop under Bandwidth-Constrained is carried out to effective scheduling.Realize under limited network bandwidth resources, effectively resource distributed and utilize.
The present invention realizes like this: construct a kind of track traffic field bus system, comprise multiple independently control loops, each control loop comprises that controller, actuator, controlled device, slip simplify device; Controller is for generation of control signal; Actuator is for being reduced to by control signal the control action that acts on controlled device; Controlled device is also equipped with sensor, and sensor is used for the real response that gathers controlled device being moved and being converted to sampled data; Slip is simplified device for sampled data is slided and simplified processing, and will deliver to controller through the sampling data transmitting of simplifying processing.
Track traffic field bus system of the present invention also comprises transmission network, for by controller generate control signal be transferred to actuator device and by slip simplify device generate simplify data transmission to controller.Each is the shared whole transmission network of control loop independently, and each independence control networks network uses the different links in transmission network.
Track traffic field bus system of the present invention also comprises scheduler, and scheduler is dispatched slip in each control loop simultaneously and simplified the data of device and controller and send.Be that scheduler is according to the priority height for sending data in each independent loop, the order that data dispatching sends and the time delay of delayed delivery data.
Each individual control loop of track traffic field bus system of the present invention is realized the control to controlled device like this: controller generates control signal; Control signal transfers to controller by transmission network; Controller is converted into the control action to controlled device by control signal after receiving control signal, realizes the control to controlled device; Controlled device also gathers and is converted to sampled data by the sensor of self to the real response action of controlled device simultaneously, and sampled data has reflected the virtual condition of controlled device; Sensor is delivered to the sampling data transmitting collecting to slide and is simplified device, slip is simplified device sampled data is slided after simplifying and sent it back controller by transmission network, controller is by the sampled data reduction after simplifying, and compare with corresponding control signal, simplify device and controller according to comparison result to determine the transmission of next control signal and to supply scheduler to dispatch to slide according to control performance.
In the present invention, the sensor of each control loop adopts cycle triggering for generating to the sampled data of controller; Control signal from controller to actuator adopts Event triggered to produce.
The present invention also provides a kind of using method of track traffic field bus system, is applicable to above-mentioned track traffic field bus system.The using method of track traffic field bus system comprises the following steps: S1) controller of each independence control networks network sends a control signal to transmission network; S2) each independently control signal be sent to by the different links of transmission network the actuator that each control loop is corresponding; S3) control signal receiving is converted to the control action to controlled device by each actuator, realizes the control to controlled device; S4) sensor of the controlled device of each control loop gathers and is converted to sampled data to the real response action of controlled device; S5) device is simplified in the slip that the sensor of each control loop is delivered to sampling data transmitting in each control loop loop, and slip is simplified device sampled data is slided and simplified; S6) each slip simplified device the sampling data transmitting after simplifying delivered to the controller of corresponding control loop, and controller reduction sampled data also contrasts with corresponding control signal; S7) controller in each loop determines the transmission of next control signal according to comparing result, and scheduler is simplified device to the controller in each control loop with slip according to the comparing result of each control loop taking of transmission network dispatched.
As transmission network of the present invention, adopt following methods to represent the state of each control loop:
Wherein A
i∈ R
n × n, B
i∈ R
1 × n, C
i∈ R
n × 1for the parameter of system,
be the state of i control loop,
be the control signal of i control loop,
it is the measuring-signal of i control loop.
Slip of the present invention is simplified device and is carried out following processing for the sampled data of sensor collection:
Q(y)=(Q
pre+S
cur·Δ)/2
Wherein Q (y) simplifies device for sliding this sends to the signal value of controller, Q
prefor the last time sends to the signal value of controller, S
curfor this sampled value of being imported into by sensor, Δ is for simplifying step-length, Δ > 0.
Especially, for first sampled value, slip is simplified device sampled value is simplified as the slip that sends to for the first time controller, described step signal value,
Q(1)=S
cur
One as the using method of track traffic field bus system of the present invention is improved, and in the time that S2 and S6 system are carried out data transmission by transmission network, introduces the coping mechanism of data packet loss.Due in the time that transmission delay is greater than the sampling period, a rear signal can cover last signal, and the present invention, using the time delay that is greater than the sampling period as packet loss processing, improves system reliability.
The using method of this kind of track traffic field bus system providing, wherein the dispatching method of scheduler is as follows: S71) scheduler initialization, the sensor sample cycle of each individual control loop and slip are simplified device and are simplified step-length and be set to original value; S72) read the control performance in each loop, obtain the comparing result of each circuit controls signal and corresponding sample data; S73) scheduler judges whether to dispatch system, judge whether to change each control loop sampling period, simplify the priority of step-length, each loop transmitted signal etc., if skip to step S75 without scheduling; S74) if desired scheduling, scheduler change each control loop sampling period, simplify the priority of step-length, each loop transmitted signal; S75) complete after once scheduling, scheduler judges whether each control loop needs to continue to control controlled device, if jump to step S72, otherwise finishes scheduling.
For the dispatching method of the scheduler the present invention relates to, the control loop performance in step S72 is by the deviation of sampled data and corresponding control signal and reduce the system resource that deviation consumes and reflect, concrete can be expressed as:
Wherein, Δ t represents a period of time interval, e
k(t) represent the error of the control loop in this moment, J
irepresent the cost function of i control loop, J
iless expression deviation is less, and control performance is better.
Implement above-mentioned track traffic field bus system and using method thereof provided by the invention, bring following beneficial effect: simplified sampled signal and solved the resource-constrained problem of multiloop network control system by slip, the step-length of simplifying device by adopting dynamic change to slide has realized effectively dispatches the bus system in the multi-control loop under Bandwidth-Constrained.Realize under limited network bandwidth resources, effectively resource distributed and utilize, improved stability and the reliability of system.
Embodiment
Below in conjunction with accompanying drawing, the present invention is described in detail.
Fig. 1 is comprehensive monitoring system (the Integrated Supervisory Control System the present invention relates to, be called for short ISCS) hierarchy chart, the ISCS system in Fig. 1 comprises two-stage management (central authorities, station), three grades of controls (central authorities, station and scene).At central level can supervision equipment running status, failure condition in each station system compass of competency of whole circuit, and to each website issuing command, assume unified command of, coordinate the operation of each website; The monitoring function of station level equipment has been mainly the monitoring of this site apparatus, management; Field level is as station level, monitored object at central level, be the main body of station subway electromechanical equipment, these monitored objects comprise environment and equipment monitoring system (BAS), automatic fire alarm system (FAS), electric power monitoring system (PSCADA), shield door (PSD), prevent flooding door (FG), a TV monitoring system (CCTV), passenger information system (PIS), signal system (SIG), AFC system (AFC), gate control system (ACS), broadcast system (PA) etc.The controller of track traffic bus detection system of the present invention is positioned at central level or station level; Controlled device is positioned at field level.
In Fig. 1, ISCS station level, local monitor network using 100M/1000M Redundant Ethernet at central level build, and underlying device key-course (field level) uses bus mode interconnected.The fieldbus using in track traffic has Profibus, Modbus, and CANbus etc., as shown in Figure 1, in the time of the continuous expansion of Rail traffic network control system scale, will there will be system control performance to reduce and the problem of resource utilization reduction.
Fig. 2 is the system construction drawing of track traffic field bus system of the present invention, for improving system control performance and the resource utilization of Fig. 1 system.System comprises multiple independently control loops, and for example one of them control loop is for controlling the shield door at station, and another control loop is for controlling the fire alarm system at station, independent of one another between control loop; Each control loop includes controller, and take the control loop of controlling vehicle shield door as example, this controller is for generation of controlling the unlatching of shield door or the control signal of cutting out; Each control loop also comprises actuator, and in shield door control loop, this actuator is solenoid valve, for responsive control signal, produces control action; Controlled device is positioned at the field level of system, and for example shield door is also equipped with sensor in controlled device, as shield door positioning indicator, can periodically gather the state of shield door; Each control loop is also equipped with to slide simplifies device, slides and simplifies the sensor of device communication connection controlled device, the sampled data of sensor collection can be slided and is simplified processing; Slip is simplified device after sampled data is slided simplifying, and simplifies data transmission to controller by what generate, allows controller compare with corresponding control signal.
Track traffic field bus system in Fig. 2 also includes transmission network.Preferably, this transmission network offers whole control loops and uses, i.e. such as shield door control loop, broadcast system loop etc., and public shared same transmission network, just uses the different link transmission datas in transmission network.In control loop, controller is connected by transport network communication with actuator, slip is simplified device and is connected by transport network communication with controller, transmission network passes and controls signal to field level for transmitting from central level, station level, and field level is uploaded to slide and simplified signal at central level or station level.Transmission network can produce the phenomenon of packet loss in the time of transmission data, and in the time that transmission delay is greater than the sampling period, a rear signal can cover last signal, and the present invention, using the time delay that is greater than the sampling period as packet loss processing, improves system reliability.
Track traffic field bus system in Fig. 2, also includes a scheduler, sends the order of data dispatching transmission and the time delay of delayed delivery data for dispatching the signal of whole transmission network.The comparing result that scheduler is simplified signal according to controller compared with control signal and corresponding slip is dispatched.
Fig. 3 is the workflow diagram of track traffic field bus system of the present invention, is applicable to the track traffic field bus system of Fig. 2.The using method of track traffic field bus system comprises the following steps: S1) controller of each independence control networks network transmits control signal, for example shield door control loop sends the control signal that shield door is closed, and Broadcasting Control loop sends to control to broadcast sends the signal that prompting shield door is closed; S2) each independently control signal be sent to by the different links of transmission network the actuator that each control loop is corresponding, the solenoid valve that is shield door at shield door control loop middle controller, in order to switch shield door, and in Broadcasting Control loop, controller is broadcast switch; S3) control signal receiving is converted to the control action to controlled device by each actuator, realizes the control to controlled device, and for example shield door is closed by solenoid control, and the loudspeaker of broadcast send prompting warning clause; S4) sensor of the controlled device in each loop gathers and is converted to sampled data to the real response action of controlled device, and status data, Broadcasting Control loop that for example shield door control loop produces shield door produce broadcast state data; S5) device is simplified in the slip that the sensor in each loop is delivered to sampling data transmitting in each loop, and slip is simplified device sampled data is slided and simplified; S6) each slip simplified device the sampling data transmitting after simplifying delivered to the controller of corresponding control loop, controller reduction sampled data also contrasts with corresponding control signal, for example, in shield door control loop, whether the control shield door shutdown signal that controller relatively sends and the slip of feedback are simplified device data and are coincide; S7) controller in each loop determines the transmission of next control signal according to comparing result, scheduler is simplified device to the controller in each control loop with slip according to the comparing result of each control loop taking of transmission network is dispatched, the state that for example ought occur shield door feedback is that shield door is still in opening, controller is from newly sending the control signal of cutting out shield door, and scheduler makes according to the comparing result scheduling Broadcasting Control loop of shield door control loop the control signal of sending alarm.
Concrete, slip is simplified device and is carried out processing for the sampled data of sensor collection:
Q(y)=(Q
pre+S
cur·Δ)/2
Wherein Q (y) simplify for sliding device this to send to the signal value of controller, for example signal value in shield door control loop be the data of shield door state through sliding after simplifying, Q
prefor the last time sends to the signal value of controller, S
curfor this sampled value of being imported into by sensor, Δ is for simplifying step-length, Δ > 0.Simplifying step-length is dynamic change, can change according to the data transmission priority of control loop etc.
Slide and simplify device to send to the signal value of controller be that a upper sending value adds that this sampled value and the product of simplifying step-length are averaged again.
Especially, for first sampled value, slide and simplify device using sampled value as the signal value that sends to for the first time controller,
Q(1)=S
cur
Concrete, in the time that S2 and S6 system are carried out data transmission by transmission network, introduce the coping mechanism of data packet loss.Take the packet loss of transmission network in S6 step as example, packet loss is described as:
Wherein
for constant,
represent not occur packet loss,
represent to have occurred packet loss.For following network system:
Wherein A
i∈ R
n × n, B
i∈ R
1 × n, C
i∈ R
n × 1for the parameter of system,
be the state of i control loop,
be the control signal of i control loop,
it is the measuring-signal of i control loop.
After simplifying device through sliding, have:
Wherein
simplify error, ∈ for sliding
iit is the error factor of simplifying of i control loop.
In the time considering packet loss, have:
Be control loop state:
And
The state of control loop and corresponding error are:
Below in conjunction with Fig. 4, the specific works flow process of scheduler is elaborated.The dispatching method of scheduler is as follows: S71) scheduler initialization, the sensor sample cycle of each individual control loop and slip are simplified device and are simplified step-length and be set to original value; S72) read the control performance in each loop, obtain the comparing result of each circuit controls signal and corresponding sample data, for example, read the control signal sending in shield door control loop and corresponding slip that receive simplified the comparing result of signal; S73) scheduler judges whether to dispatch system, judge whether to change each control loop sampling period, simplify the priority of step-length, each loop transmitted signal etc., if skip to step S75 without scheduling, for example, in shield door control loop, if it is good that scheduler is judged the control performance of control loop,, without this control loop is dispatched, go to step S75; S74) if desired scheduling, scheduler change each control loop sampling period, simplify the priority of step-length, each loop transmitted signal, for example, in shield door control loop, if there is shield door responsive control signal not in time, control performance is poor, this control loop is dispatched, and the method for scheduling comprises the raising sampling period, step-length is simplified in adjusting, and the network that improves shield door control loop transmits signal and sends priority etc.; S75) complete after once scheduling, scheduler judges whether each control loop needs to continue to control controlled device, if jump to step S72, otherwise finishes scheduling.For the control loop that needs Sustainable Control, the next comparing result of scheduler waits, again reads after comparing result and to dispatch judging whether, until control loop finishes the control to controlled device.
Control loop performance is by the deviation of sampled data and corresponding control signal and reduce the system resource that deviation consumes and reflect, concrete can be expressed as:
Wherein, Δ t represents a period of time interval, e
k(t) represent the error of the control loop in this moment, J
irepresent the cost function of i control loop, J
iless expression deviation is less, and control performance is better.
For the dispatching method of scheduler, in the time of system initialization, first a basic sampling period is set and simplifies step-length according to system configuration, and carry out priority distribution according to type of message: the signal with schedule information has higher priority, the signal of Event triggered has inferior priority, and the signal that sensor sends has the 3rd class priority.System is dispatched according to performance index J, and scheduler periodically reads the control index of each control loop, and its summation is obtained to system performance overall performance J
sys, work as J
syswhile being greater than the value of setting, represent system performance variation, now need suitably to regulate the sampling period.Work as J
syswhile being less than the value of setting, sort to the J in each loop is ascending, observe the poorest J of its performance
loopwhether in the scope of setting, as exceed its scope, the adjustable step-length of simplifying, to improve the control performance in this loop.The network dispatcher calculating sampling cycle and simplify step-length and with periodically packet send, notify each node effectively to upgrade.
Below in conjunction with accompanying drawing, a system embodiment with three individual control loops elaborates the beneficial effect that dispatching office of the present invention produces.
Fig. 5 is the present invention's specific embodiment first, has three individual control loops, and the control object of each control loop is G (s)=1000/ (s that adopts direct current generator
2+ s), the employing PID of controller node controls, and wherein concrete control parameter is K=0.85, T
i=0.16, T
d=0.095, network type is CSMA/AMP (CAN) bus, and CAN bus communication baud rate is 500K, and initially the employing cycle is 10ms.
For the control loop 3 in Fig. 5, be set as priority lower, for the system performance before not dispatching as shown in Figure 6.Control loop 3 is because priority is lower, cause the real-time of system to be affected, system concussion aggravation, make control performance degradation, the priority in loop 1 and loop 2 is higher, more easily obtain Internet resources, its control performance is also relatively good, but overall performance has not been well positioned to meet control requirement.
Fig. 7 is the control performance figure adding after scheduling.The system stability post-sampling cycle is 8.4ms, the step parameter of simplifying that device is simplified in the slip of each loop is respectively, the control effect of three control loops is not quite similar, but overall system control performance has obtained optimization, and particularly the control performance of control loop 3 is significantly optimized.That is to say, reduced the probability of each signal conflict by simplifying periodic scheduling, the transfer rate of low priority message has obtained larger improvement, makes multiloop control system under limited bandwidth situation, guarantee the control requirement of system.
From Fig. 6 and Fig. 7 relatively: adopt dispatching method of the present invention can improve stability and the reliability of system.
These are only preferred embodiment of the present invention, can not limit with this scope of the embodiment of the present invention, equalization that those skilled in the art in the art do according to this creation changes, and the change known of those skilled in that art, all should still belong to the scope that the present invention is contained.