A fleet cooperative control system state observer and its observation method

Abstract

The present invention provides a fleet collaborative control system state observer and an observation method thereof, which relates to the technical field of networked collaborative control. It includes a vessel state separator, a quantizer, an encoder, a wireless transmitter, a wireless communication network, a wireless receiver, and a system state estimator connected in sequence. The vessel state separator separates the vessel state, extracts the state information of the fleet collaborative control system, quantizes it through the quantizer, performs source coding and channel coding through the encoder, and then sends it to the wireless communication network through the wireless transmitter. After receiving the data packet through the wireless receiver, the system state estimator decodes and calculates the state observation value of the fleet collaborative control system, and provides it to the controller to ensure the coordinated control of the system, and reduces the impact on collaborative control caused by problems such as data packet transmission time delay and out-of-order under the condition of ensuring that the system control performance is satisfied.

Description

Technical Field

[0001] The present invention relates to the technical field of networked cooperative control, and particularly to a state observer for a fleet cooperative control system and an observation method thereof. Background Art

[0002] In marine fisheries and ocean cargo transportation, control problems such as autonomous formation navigation of ships, fleet cooperative operation, and navigation cooperative management have received increasing attention. Fleets need to interact with each other, cooperate and control, especially in areas with dangerous goods navigation, difficult navigation areas, high navigation density and harsh environments. Through the fleet cooperative control system, ships can be effectively managed, the navigation routes of ships can be coordinated, and the safety of all ships can be ensured.

[0003] In recent years, Internet of Things (IoT) technology has been widely applied in various industries, and product research and development based on the IoT has received more and more attention, greatly promoting the development of networked control systems. In addition, the rise of artificial intelligence technology has also realized intelligent ship management systems. Based on key technologies such as the IoT, artificial intelligence, and cooperative control, a fleet cooperative control system can effectively solve problems such as management control, navigation safety, and information exchange during fleet navigation, and can greatly improve work efficiency.

[0004] In the fleet cooperative control system, all ships need to timely master each other's navigation states, including state information such as the position, attitude, speed, and angular velocity of the ships, that is, the state of the fleet cooperative control system. Based on the state of the fleet cooperative control system, a cooperative control algorithm can be formulated to effectively control all ships. The state of the fleet cooperative control system is transmitted to all ships in the fleet through the IoT.

[0005] Generally, when fleets are sailing on rivers and seas, they will be disturbed by environmental changes such as wind, waves, and currents, and the fleet navigation trajectories change in real time. The change of the navigation conditions of the controlled ships will also cause uncertainties in the states. In addition, when fleets are sailing on rivers and seas, the wireless communication network will also be affected by spatial noise and interference. In severe cases, it will cause the fleet cooperative control system to be unstable, thus completely losing the cooperative control of the fleet.

[0006] Due to the influence of noise and interference in the navigation environment, transmission data packets will be lost. To solve this problem, the IoT adopts the IP / TCP network protocol to retransmit the lost data packets. Unfortunately, the retransmitted data packets will cause problems such as time delay and out-of-order.

[0007] Currently, how to design a state observer for a fleet cooperative control system, adopt an effective observation method, and reduce the influence of problems such as data packet transmission time delay and out-of-order on cooperative control is a key technical problem to be solved. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a state observer for a fleet cooperative control system and its observation method in view of the deficiencies of the above-mentioned prior art, so as to effectively observe the state of the fleet cooperative control system, ensure the coordinated control of the system, and reduce the impact of problems such as data packet transmission time delay and out-of-order on cooperative control while ensuring that the system control performance requirements are met.

[0009] To solve the above technical problem, the technical solution adopted by the present invention is as follows:

[0010] On the one hand, the present invention provides a state observer for a fleet cooperative control system, including a ship state separator, a quantizer, an encoder, a wireless transmitter, a wireless communication network, a wireless receiver, and a system state estimator connected in sequence;

[0011] The ship state separator is used to separate the position and rotation angle state information of the ship from the controlled ship state, so as to obtain the state equation of the fleet cooperative control system and the state η of the fleet cooperative control system k , and transmit it to the quantizer;

[0012] The quantizer is used to quantize the state η of the fleet cooperative control system k to obtain the quantization value of the state η of the fleet cooperative control system k ; The quantizer transmits the quantization value to the encoder;

[0013] The encoder is used to perform source coding on the quantization value to obtain the codeword C k ; then perform channel coding on the codeword C k to obtain the codeword D after channel coding k ; the codeword D after channel coding k is transmitted to the wireless transmitter;

[0014] The wireless transmitter is used to receive the codeword D k , and modulate the codeword D k and then send it to the wireless communication network;

[0015] The wireless communication network is a communication network composed of all the wireless transmitters in the fleet, and is used to transmit the codewords sent by each ship in the fleet to the wireless receivers of each other;

[0016] The wireless receiver is used to receive the signal sent by the wireless communication network, convert the received signal into a data packet, and then send the data packet to the system state estimator;

[0017] The system state estimator is used to decode the received data packet to obtain the codeword Estimate the state of the fleet cooperative control system, calculate the state of the controlled vessel, and transmit it to the controller.

[0018] Furthermore, the vessel state separator includes a vessel output acquisition module, a linearization conversion module, a full - order state observer, and a vessel state decoupling module;

[0019] The vessel output acquisition module is used to obtain the measurable output value of the controlled vessel from the sensor, perform periodic sampling and analog - to - digital conversion on the measurable output value, and transmit the digitized measurable output value of the controlled vessel to the linearization conversion module;

[0020] The linearization conversion module is used to linearize the vessel state equation and obtain the controlled vessel state equation, expressed as:

[0021] T k+1 =GT k +BU k +FW k

[0022] S k =LT k

[0023] U k =C u S k

[0024] Where, T k ∈R n represents the state of the controlled vessel; U k ∈R p represents the output variable of the controller; S k ∈R q represents the measurable output of the controlled vessel; W k ∈R o represents the system disturbance signal; G, B, L, F, C u are matrices of appropriate dimensions; the linearization conversion module transmits the controlled vessel state equation and S k to the full - order state observer;

[0025] The full - order state observer is used to calculate the state observation value of the controlled vessel. The full - order state observer is shown as follows:

[0026]

[0027] Where, represents the state observation value of the controlled vessel; E is the state gain matrix of this full - order state observer; the full - order state observer transmits to the vessel state decoupling module;

[0028] The vessel state decoupling module is used to decouple the controlled vessel state equation after linearization; let η k =[x k y k z k φ k θ k ψ k T represent the state of the fleet cooperative control system, where x k represents the translational variable along the x n axis in the north-east coordinate system, y k represents the translational variable along the y n axis in the north-east coordinate system, z k represents the translational variable along the z n axis in the north-east coordinate system, φ k represents the rotational angle along the x b axis in the hull coordinate system, θ k represents the rotational angle along the y b axis in the hull coordinate system, ψ k represents the rotational angle along the z b axis in the hull coordinate system; let H represent a non-singular matrix, then we get:

[0029]

[0030] where, is the transformation matrix of G; G s is separated, and it is the system matrix corresponding to the state of the fleet cooperative control system; G v is the system matrix corresponding to the states of other controlled vessels;

[0031] Define:

[0032]

[0033] B = H -1 [B s B d

[0034] F = H -1 [F s F d

[0035]

[0036]

[0037] where, represents the state values other than the state of the fleet cooperative control system; is corresponding to the state η of the fleet cooperative control system​​​k The control input variable is the remaining control input variables is corresponding to the state η of the fleet cooperation control system k of the disturbance variable represents the remaining disturbance variables, B s 、B d 、F d and F s are the corresponding matrices; represents the state observation value obtained through the state observer of the fleet cooperation control system;

[0038] Then the state equation of the fleet cooperation control system is obtained as follows:

[0039]

[0040]

[0041] The vessel state separator transmits the state equation of the fleet cooperation control system and the state η of the fleet cooperation control system k to the quantizer.

[0042] Furthermore, the quantization method of the quantizer adopts uniform quantization, and the number of quantization levels is m.

[0043] Furthermore, the source coding is encoded by using the binary equal-length coding method, and the codeword length is L; the length L of the codeword C is calculated by the following formula k :

[0044] L = 6log 2 m

[0045] The channel coding is encoded by using the binary (N, L) block code coding method, where N ∈ Z is the codeword length of the codeword D after channel coding k of.

[0046] Furthermore, the system state estimator includes a decoding module, a queuing module, a system state calculation module, a system state prediction module, and a vessel state synthesis module;

[0047] The decoding module is implemented by using the maximum a posteriori probability decoding method, and is used to obtain the received code R based on the data packet transmitted by the wireless receiver k , and after decoding the received code R k to obtain the codeword Based on the codeword perform channel decoding to obtain the codeword Then based on the codeword perform source decoding to obtain the quantization value of the state of the fleet cooperation control system Finally, the obtained quantization value Transmitted to the queuing module; the codeword obtained after decoding is:

[0048]

[0049] where d i is the i-th available codeword among all the codewords obtained by the encoder through channel encoding of the codeword C k ; p(d i |R k ) represents the probability of d k occurring under the condition of a given R i ;

[0050] The queuing module is used to sort the received system state quantization values ; the queuing module has a time synchronization function, numbers and stores the received system state quantization values , and reorders the system state quantization values with time delay and out-of-order , and then sends the sorted system state quantization values to the system state calculation module;

[0051] The system state prediction module is used to calculate the system state prediction value when there is a time delay in the transmission of the system state quantization value, and transmits it to the system state calculation module to ensure that the system state calculation module calculates the system state observation value The calculation method of the system state prediction value by the system state prediction module is as follows:

[0052]

[0053] The system state calculation module is used to calculate the fleet cooperative control system state observation value based on the system state quantization values sent by the queuing module and transmit the calculated system state observation value to the vessel state synthesis module; if there is no time delay in the transmission of the system state quantization value, the system state calculation module directly uses the system state quantization value sent by the queuing module as the system state observation value ; if there is a time delay in the transmission of the system state quantization value, the system state calculation module uses the system state prediction value provided by the system state prediction module as the system state observation value

[0054] The vessel state synthesis module is used to obtain the fleet cooperative control system state observation value Combined with the vessel status information measured by the sensor, the overall status information of the vessel is further synthesized and provided to the controller for state feedback control, thereby realizing the cooperative control of the fleet.

[0055] On the other hand, the present invention also provides a method for observing the state of a fleet cooperative control system, which is implemented by using the above-mentioned fleet cooperative control system state observer, and includes the following steps:

[0056] Step 1: Through vessel status separation, obtain the vessel position and rotational angle status information of the controlled vessel, thereby obtaining the state equation of the fleet cooperative control system and the state η of the fleet cooperative control system k ;

[0057] Step 2: Quantify the state η of the fleet cooperative control system k to obtain a quantization value

[0058] Step 3: Encode the quantization value of the state of the fleet cooperative control system ;

[0059] Step 4: Modulate the encoded codeword D k through a wireless transmitter and send it to the wireless communication network;

[0060] Step 5: The wireless communication network transmits the codewords sent by each vessel in the fleet to the wireless receivers of each other;

[0061] Step 6: Receive the signal from the wireless communication network through the wireless receiver and convert it into a data packet and send it to the system state estimator;

[0062] Step 7: Calculate the system state observation value through the system state estimator and calculate the state information of the controlled vessel.

[0063] Further, the specific method of Step 1 is as follows:

[0064] Step 1.1: Obtain the measurable output value of the controlled vessel from the sensor, and perform periodic sampling and analog-to-digital conversion on the measurable output value;

[0065] Step 1.2: Linearize the vessel state equation to obtain the controlled vessel state equation, expressed as:

[0066] T k+1 = GT k + BU k + FW k

[0067] S k = LT k

[0068] U k = Cu S k

[0069] where T k ∈R n represents the state of the controlled vessel; U k ∈R p represents the output variable of the controller; S k ∈R q represents the measurable output of the controlled vessel; W k ∈R o represents the system disturbance signal; G, B, L, F, C u are matrices of appropriate dimensions;

[0070] Step 1.3: Based on the state equation of the controlled vessel in Step 1.2 and S k , calculate the state observation value of the controlled vessel through a full - order state observer, as shown in the following equation:

[0071]

[0072] where represents the state observation value of the controlled vessel; E is the state gain matrix of this full - order state observer;

[0073] Step 1.4: Decouple the state equation of the controlled vessel after linearization to obtain the state η k of the fleet cooperative control system; the specific method is:

[0074] Let η k = [x k y k z k φ k θ k ψ k T represents the state of the fleet cooperative control system, where x k represents the translational variable along the x n axis in the north - east coordinate system, y k represents the translational variable along the y n axis in the north - east coordinate system, z k represents the translational variable along the z n axis in the north - east coordinate system, φ k represents the rotational angle along the x b axis in the hull coordinate system, θ k represents the rotational angle along the y b axis in the hull coordinate system, ψ k represents the rotational angle along the z b axis in the hull coordinate system; let H represent a non - singular matrix, then we get: ​

[0075]

[0076] Among them, is the transformation matrix of G; G s is separated, and is the system matrix corresponding to the state of the fleet cooperative control system; G v is the system matrix corresponding to the states of other controlled vessels;

[0077] Definition:

[0078]

[0079] B = H -1 [B s B d

[0080] F = H -1 [F s F d

[0081]

[0082]

[0083] Among them, represents the state value other than the state of the fleet cooperative control system; is the control input variable corresponding to the state η of the fleet cooperative control system k ; is the remaining control input variable, is the disturbance variable corresponding to the state η of the fleet cooperative control system k ; represents the remaining disturbance variable, B s 、B d 、F d and F s are the corresponding matrices; represents the state observation value obtained through the state observer of the fleet cooperative control system;

[0084] Then, the state equation of the fleet cooperative control system is obtained:

[0085]

[0086]

[0087] Furthermore, the quantization method in step 2 adopts uniform quantization, and the number of quantization levels is m.

[0088] Furthermore, the specific method of step 3 is:

[0089] ​​Step 3.1: Perform source coding on the quantization value η k to obtain the codeword C k ; The source coding method uses a binary fixed-length coding method, and the codeword length is L; Calculate the codeword C through the following formula k Codeword length L:

[0090] L = 6log 2 m

[0091] Step 3.2: Perform channel coding on the codeword C k to obtain the codeword D after channel coding k ; The channel coding method uses a binary (N, L) block code coding method, where N ∈ Z is the codeword length of the codeword D k after channel coding.

[0092] Furthermore, the specific method of step 7 is as follows:

[0093] Step 7.1: Obtain the received code R k based on the data packet transmitted by the wireless receiver, and the codeword obtained after decoding it is:

[0094]

[0095] where d i is the i-th available codeword among all the codewords obtained by the encoder performing channel coding on the codeword C k ; p(d i |R k ) represents the probability of d k occurring under the condition of a given R i ;

[0096] Step 7.2: Perform channel decoding based on the codeword obtained after decoding to obtain the codeword

[0097] Step 7.3: Perform source decoding based on the codeword to obtain the quantization value of the fleet cooperative control system state

[0098] Step 7.4: Number and store the received system state quantization value , and reorder the system state quantization values with time delay and out-of-order;

[0099] Step 7.5: Calculate the state observation value of the fleet cooperative control system based on the reordered system state quantization value The specific method is:

[0100] If there is no time delay in the transmission of the system state quantization value, the system state quantization value with the reordered sequence obtained directly by step 7.4 is used as the system state observation value

[0101] If there is a time delay in the transmission of the system state quantization value, the system state predicted value is used as the system state observation value System state predicted value The calculation method is as follows:

[0102]

[0103] Let θ represent whether a delay has occurred; when there is a time delay in the transmission of the system state quantization value, define θ = 1; when there is no time delay in the transmission of the system state quantization value, define θ = 0; then the state observation value of the fleet cooperative control system has the following calculation formula:

[0104]

[0105] Step 7.6: Add the state information of the ships measured by the sensors to the state observation value of the fleet cooperative control system obtained in step 7.5 to further synthesize all the state information of the ships and provide it to the controller

[0106] The beneficial effects of adopting the above technical solutions are as follows: The state observer and its observation method for the fleet cooperative control system provided by the present invention give a state observer and its observation method for the situation of time delay and out-of-order transmission of the system state in the wireless communication network, realize the effective observation of the state of the fleet cooperative control system, reduce the influence of the time delay and out-of-order transmission of the system state in the wireless communication network, and ensure that the fleet cooperative control system can effectively implement control Brief Description of the Drawings

[0107] Figure 1 is a schematic structural diagram of the fleet cooperative control system provided by an embodiment of the present invention

[0108] Figure 2 is a structural block diagram of the state observer of the fleet cooperative control system provided by an embodiment of the present invention

[0109] Figure 3 is a schematic diagram of the principle of the ship state separator provided by an embodiment of the present invention

[0110] Figure 4 is a schematic diagram of the principle of the system state estimator provided by an embodiment of the present invention Detailed Embodiment

[0111] ​The specific embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0112] The fleet collaborative control system, such as Figure 1 shown, includes controlled vessels, sensors, a fleet collaborative control system state observer, a controller, an actuator, etc. This embodiment provides a fleet collaborative control system state observer and its observation method, which are mainly applicable to the fleet collaborative control system, and are particularly suitable for realizing the effective observation of the system state by all vessels, ensuring the coordinated control of the system, and reducing the impact of problems such as data packet transmission time delay and out-of-order on the collaborative control while ensuring that the system control performance is met. The fleet collaborative control system state observer of this embodiment, such as Figure 2 shown, includes a vessel state separator, a quantizer, an encoder, a wireless transmitter, a wireless communication network, a wireless receiver, and a system state estimator connected in sequence.

[0113] The vessel state separator is used to separate the position and rotation angle state information of the vessel from the controlled vessel state, so as to obtain the fleet collaborative control system state equation and the fleet collaborative control system state η k , and transmit it to the quantizer. The vessel state separator, such as Figure 3 shown, includes a vessel output acquisition module, a linearization conversion module, a full-dimensional state observer, and a vessel state decoupling module.

[0114] The vessel output acquisition module is used to obtain the measurable output value of the controlled vessel from the sensor, and then perform periodic sampling and analog-to-digital conversion on the measurable output value, and transmit the digitized measurable output value of the controlled vessel to the linearization conversion module.

[0115] The linearization conversion module is used to linearize the vessel state equation to obtain the controlled vessel state equation, which is expressed as:

[0116] T k+1 = GT k + BU k + FW k

[0117] S k = LT k

[0118] U k = C u S k

[0119] where, T k ∈R n represents the controlled vessel state; U k ∈R pDenote the output variable of the controller; S k ∈R q Denote the measurable output of the controlled vessel; W k ∈R o Denote the system disturbance signal; G, B, L, F, C u are matrices of appropriate dimensions. The linearization transformation module transmits the state equation of the controlled vessel and S k to the full - order state observer.

[0120] In the vessel state separator, based on the above - mentioned state equation of the controlled vessel and S k , a full - order state observer is used to calculate the state observation value of the controlled vessel, as shown in the following formula:

[0121]

[0122] where, Denote the state observation value of the controlled vessel; E is the state gain matrix of this full - order state observer. The full - order state observer transmits to the vessel state decoupling module.

[0123] The vessel state decoupling module is used to decouple the state equation of the controlled vessel after linearization. Let η k =[x k y k z k φ k θ k ψ k T Denote the state of the fleet cooperative control system, where x k Denote the translational variable along the x n axis in the north - east coordinate system, y k Denote the translational variable along the y n axis in the north - east coordinate system, z k Denote the translational variable along the z n axis in the north - east coordinate system, φ k Denote the rotational angle along the x b axis in the hull coordinate system, θ k Denote the rotational angle along the y b axis in the hull coordinate system, ψ k Denote the rotational angle along the z b axis in the hull coordinate system. Let H denote a non - singular matrix, then we get:

[0124]

[0125] where, is the transformation matrix of G; G s ​is the separated system matrix corresponding to the state of the fleet cooperative control system; G v is the system matrix corresponding to the states of other controlled vessels.

[0126] In addition, define:

[0127]

[0128] B = H -1 [B s B d

[0129] F = H -1 [F s F d

[0130]

[0131]

[0132] where, represents the state values other than the state of the fleet cooperative control system; is the control input variable corresponding to the state η k of the fleet cooperative control system, are the remaining control input variables, is the disturbance variable corresponding to the state η k of the fleet cooperative control system, represents the remaining disturbance variables, B s 、B d 、F d and F s are the corresponding matrices; represents the state observation value obtained through the state observer of the fleet cooperative control system.

[0133] Then, the state equation of the fleet cooperative control system is obtained:

[0134]

[0135]

[0136] The vessel state separator transmits the state equation of the fleet cooperative control system and the state η k of the fleet cooperative control system to the quantizer.

[0137] The quantizer is used to quantize the state η k of the fleet cooperative control system to obtain the quantized value k of the state η The quantizer sends the quantized value ​​Transmitted to the encoder. The quantization method uses uniform quantization, and the number of quantization levels is m.

[0138] The encoder is used to perform source coding on the quantized value to obtain the codeword C k . The source coding is performed using binary fixed-length coding method, and the codeword length is L. The length L of the codeword C is calculated by the following formula k :

[0139] L = 6log 2 m

[0140] After the quantized value is encoded, a codeword with length L can be obtained. Considering the influence of noise and interference in the wireless communication network, which may cause data transmission errors, the encoder needs to perform channel coding on the codeword C k to obtain the codeword D after channel coding k . The channel coding is performed using binary (N, L) block code coding method, where N ∈ Z is the codeword length of the codeword D after channel coding k . The codeword D after channel coding k is transmitted to the wireless transmitter.

[0141] The wireless transmitter is used to receive the codeword D k , and modulate the codeword D k and then send it to the wireless communication network. In this embodiment, the hardware circuit of the wireless transmitter uses the wireless communication module CC2530 to implement data communication. CC2530 is an IoT node chip that executes the IEEE802.15.4 protocol. After receiving the codeword D k , the wireless transmitter modulates it through the wireless communication module CC2530 and sends it to the wireless communication network.

[0142] The wireless communication network is a communication network composed of all the wireless transmitters in the fleet, and is used to transmit the codewords sent by each ship in the fleet to the wireless receivers of each other.

[0143] The wireless receiver is used to receive the signal sent by the wireless communication network, convert the received signal into a data packet, and then send the data packet to the system state estimator. In this embodiment, the hardware circuit of the wireless receiver also uses the wireless communication module CC2530.

[0144] The system state estimator is used to decode the received data packet according to the received data packet to obtain the codeword Considering the influence of data packet transmission time delay and out-of-order, estimate the state of the fleet cooperative control system, calculate the state of the controlled ship, and transmit it to the controller. The system state estimator is as Figure 4As shown, it includes a decoding module, a queuing module, a system state calculation module, a system state prediction module, and a vessel state synthesis module.

[0145] The decoding module is implemented using the Maximum A Posteriori Probability (MAP) decoding method and is used to obtain the received code R based on the data packets transmitted by the wireless receiver k , and after decoding the received code R k , the codeword is obtained Based on the codeword , channel decoding is performed to obtain the codeword Then, based on the codeword , source decoding is performed to obtain the quantization value of the vessel fleet cooperative control system state Finally, the obtained quantization value is transmitted to the queuing module. The codeword obtained after decoding is as follows:

[0146]

[0147] where d i is the i-th available codeword among all the codewords obtained by the encoder performing channel coding on the codeword C k ; p(d i |R k ) represents the probability of d k occurring under the condition of a given R i .

[0148] The queuing module is used to sort the received quantization values of the system state . When vessels sail on rivers and seas, the wireless communication network is also affected by spatial noise and interference, resulting in the loss of some transmitted data packets. The wireless communication network in this embodiment uses the IP / TCP network protocol to retransmit the lost data packets. Unfortunately, the retransmitted data packets will cause problems such as time delay and out-of-order. The TCP protocol in the wireless communication network works in the transport layer of the OSI. It is a reliable connection-oriented data stream protocol. In the TCP protocol, the order of data packets is guaranteed by a sequence number. When the TCP transmits a data packet, a timer is started at the same time. If the confirmation information is not received when the timer times out, it is determined that the data packet is lost, and then the data packet must be retransmitted. When the data packet is received, it will cause time delay or out-of-order, resulting in the quantization value of the system state having time delay or out-of-order. The queuing module has a time synchronization function, numbers and stores the received quantization values of the system state , and readjusts the order of the quantization values of the system state with time delay and out-of-order , and then sends the sorted quantization values of the system state to the system state calculation module.

[0149] The system state prediction module is used to calculate the system state prediction value when there is a time delay in the transmission of the system state quantization value and transmit it to the system state calculation module to ensure that the system state calculation module calculates the system state observation value The system state prediction module performs calculations on the system state prediction value The calculation method is as follows:

[0150]

[0151] The system state calculation module is used to calculate the fleet cooperative control system state observation value based on the system state quantization value sent by the queuing module and calculate the system state observation value and transmit the calculated system state observation value to the vessel state synthesis module

[0152] Because the wireless communication network is affected by spatial noise and interference, some of the transmitted data packets are lost, and retransmission will cause the system state quantization value to have a time delay or be out of order. Therefore, the system state calculation module cannot receive the system state quantization value on time either However, for the fleet cooperative control system, in order to achieve effective control of the controlled vessels, the system state value needs to be provided at all times. Therefore, the system state calculation module uses a prediction estimation method to calculate the fleet cooperative control system state value, that is, the fleet cooperative control system state observation value

[0153] If there is no time delay in the transmission of the system state quantization value, the system state calculation module directly uses the system state quantization value sent by the queuing module as the system state observation value If there is a time delay in the transmission of the system state quantization value, the system state calculation module uses the system state prediction value provided by the system state prediction module as the system state observation value

[0154] Let θ represent whether a delay has occurred. When there is a time delay in the transmission of the system state quantization value, define θ = 1; when there is no time delay in the transmission of the system state quantization value, define θ = 0. Then the fleet cooperative control system state observation value The calculation formula is as follows:

[0155]

[0156] The vessel state synthesis module is used to obtain the fleet cooperative control system state observation value from the system state calculation module Combined with the vessel status information measured by the sensors, the overall vessel status information is further synthesized and provided to the controller. To achieve effective cooperative control of the controlled vessel, the controller requires the overall status information of the vessel. However, the state observation value of the fleet cooperative control system is only partial status information of the vessel. Therefore, the main task of the vessel status synthesis module is to further synthesize the overall status information of the vessel based on the state observation value of the fleet cooperative control system obtained from the system state calculation module combined with the vessel status information measured by the sensors, and provide it to the controller. Based on the obtained status information of the controlled vessel, the controller implements state feedback control, thereby achieving fleet cooperative control.

[0157] A method for observing the state of a fleet cooperative control system, implemented using the above-mentioned fleet cooperative control system state observer, includes the following steps:

[0158] Step 1: Through vessel status separation, obtain the vessel position and rotational angle status information of the controlled vessel, thereby obtaining the state equation of the fleet cooperative control system and the state η of the fleet cooperative control system k ; The specific method is as follows:

[0159] Step 1.1: Obtain the measurable output value of the controlled vessel from the sensor, and perform periodic sampling and analog-to-digital conversion on the measurable output value;

[0160] Step 1.2: Linearize the vessel state equation to obtain the state equation of the controlled vessel, expressed as:

[0161] T k+1 = GT k + BU k + FW k

[0162] S k = LT k

[0163] U k = C u S k

[0164] where, T k ∈R n represents the state of the controlled vessel; U k ∈R p represents the output variable of the controller; S k ∈R q represents the measurable output of the controlled vessel; W k ∈R o represents the system disturbance signal; G, B, L, F, C u are matrices of appropriate dimensions;

[0165] Step 1.3: Based on the state equation of the controlled vessel in Step 1.2 and S k , calculate the state observation value of the controlled vessel through a full-order state observer, as shown in the following formula:

[0166]

[0167] where, represents the state observation value of the controlled vessel; E is the state gain matrix of this full-order state observer;

[0168] Step 1.4: Decouple the state equation of the controlled vessel after linearization to obtain the state η of the fleet cooperative control system k ; the specific method is:

[0169] Let η k = [x k y k z k φ k θ k ψ k T represents the state of the fleet cooperative control system, where x k represents the translational variable along the x n axis in the north-east coordinate system, y k represents the translational variable along the y n axis in the north-east coordinate system, z k represents the translational variable along the z n axis in the north-east coordinate system, φ k represents the rotational angle along the x b axis in the hull coordinate system, θ k represents the rotational angle along the y b axis in the hull coordinate system, ψ k represents the rotational angle along the z b axis in the hull coordinate system; let H represent a non-singular matrix, then we get:

[0170]

[0171] where, is the transformation matrix of G; G s is separated, and it is the system matrix corresponding to the state of the fleet cooperative control system; G v is the system matrix corresponding to the states of other controlled vessels.

[0172] In addition, define:

[0173]

[0174] B = H -1 ​[B s B d

[0175] F = H -1 [F s F d

[0176]

[0177]

[0178] wherein, represents the state value other than the state of the fleet cooperative control system; is the control input variable corresponding to the state η of the fleet cooperative control system k ; is the remaining control input variable, is the disturbance variable corresponding to the state η of the fleet cooperative control system k ; represents the remaining disturbance variables, B s 、B d 、F d and F s are the corresponding matrices; represents the state observation value obtained through the state observer of the fleet cooperative control system.

[0179] Then the state equation of the fleet cooperative control system is obtained:

[0180]

[0181]

[0182] Step 2: Quantize the state η of the fleet cooperative control system k to obtain the quantization value ; the quantization method adopts uniform quantization, and the number of quantization levels is m;

[0183] Step 3: Encode the quantization value of the state of the fleet cooperative control system ; the specific method is:

[0184] Step 3.1: Perform source coding on the quantization value to obtain the codeword C k ; the source coding method adopts binary equal-length coding method, and the codeword length is L; calculate the codeword C k length L through the following formula:

[0185] L = 6log 2 m

[0186] Step 3.2: Perform coding on the codeword C k ​​Perform channel coding to obtain the coded word D after channel coding k ; The channel coding method adopts the binary (N, L) block code coding method, where N ∈ Z is the codeword length of the coded word D k after channel coding;

[0187] Step 4: Modulate the coded word D after coding and send it to the wireless communication network through a wireless transmitter k ;

[0188] Step 5: The wireless communication network transmits the coded words sent by each ship in the fleet to the wireless receivers of each other

[0189] Step 6: Receive the signal of the wireless communication network through a wireless receiver and convert it into a data packet and send it to the system state estimator

[0190] Step 7: Calculate the system state observation value through the system state estimator and calculate the state information of the controlled ship; The specific method is as follows:

[0191] Step 7.1: Obtain the received code R based on the data packet transmitted by the wireless receiver k , and the coded word obtained after decoding it is:

[0192]

[0193] where d i is the i-th available coded word among all the coded words obtained by the encoder for channel coding the coded word C k ; p(d i |R k ) represents the probability of d k occurring under the condition of given R i ;

[0194] Step 7.2: Perform channel decoding based on the decoded coded word to obtain the coded word

[0195] Step 7.3: Perform source decoding based on the coded word to obtain the quantization value of the fleet cooperative control system state

[0196] Step 7.4: Number and store the received quantization value of the system state, and reorder the quantization values of the system state with time delay and out-of-order ; Step 7.5: Calculate the observation value of the fleet cooperative control system state based on the reordered quantization value of the system state

[0197] ; Calculate the observation value of the fleet cooperative control system state The specific method is as follows:

[0198] If there is no time delay in the transmission of the system state quantization value, the system state quantization value with the re-adjusted order in step 7.4 is directly adopted as the system state observation value

[0199] If there is a time delay in the transmission of the system state quantization value, the system state prediction value is adopted as the system state observation value System state prediction value The calculation method is as follows:

[0200]

[0201] Let θ represent whether there is a delay; when there is a time delay in the transmission of the system state quantization value, define θ = 1; when there is no time delay in the transmission of the system state quantization value, define θ = 0; then the system state observation value of the fleet cooperative control system The calculation formula is as follows:

[0202]

[0203] Step 7.6: Add the system state observation value of the fleet cooperative control system obtained in step 7.5 to the ship state information measured by the sensor, and further synthesize all the state information of the ship and provide it to the controller.

[0204] This embodiment provides a system state observer and its observation method for a fleet cooperative control system, which is mainly applicable to the fleet cooperative control system, and is particularly suitable for realizing the effective observation of the system state by all ships, ensuring the coordinated control of the system, and reducing the influence of problems such as data packet transmission time delay and out-of-order on the cooperative control while ensuring that the system control performance is satisfied.

[0205] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope defined by the claims of the present invention.

Claims

1. A state observer for a fleet collaborative control system, characterized in that: it includes a vessel state separator, a quantizer, an encoder, a wireless transmitter, a wireless communication network, a wireless receiver, and a system state estimator connected in sequence; The vessel state separator is used to separate the position and rotational angle state information of the ship from the controlled vessel state, so as to obtain the state equation of the fleet cooperative control system and the state η of the fleet cooperative control system k , and transmit it to the quantizer; The quantizer is used to quantize the state η of the fleet cooperative control system k to obtain the quantized value of the state η of the fleet cooperative control system k ; The quantizer transmits the quantized value to the encoder; The encoder is used to perform source coding on the quantization values to obtain the codeword C k ; then perform channel coding on the codeword C k to obtain the codeword D after channel coding k ; the codeword D after channel coding k is transmitted to the wireless transmitter; The wireless transmitter is used to receive the codeword D k , and modulate the codeword D k and then send it to the wireless communication network; The wireless communication network is a communication network composed of all the wireless transmitters in the fleet, and is used to transmit the codewords sent by each ship in the fleet to the wireless receivers of each other; The wireless receiver is used to receive the signal sent by the wireless communication network, convert the received signal into a data packet, and then send the data packet to the system state estimator; The system state estimator is used to decode the received data packets to obtain the codewords and estimate the state of the fleet cooperative control system, calculate the state of the controlled vessel, and transmit it to the controller.

2. The state observer for a fleet collaborative control system according to claim 1, characterized in that: The vessel state separator includes a vessel output acquisition module, a linearization conversion module, a full-order state observer, and a vessel state decoupling module; The vessel output acquisition module is used to obtain the measurable output value of the controlled vessel from the sensor, perform periodic sampling and analog-to-digital conversion on the measurable output value, and transmit the digitized measurable output value of the controlled vessel to the linearization conversion module; The linearization conversion module is used to linearize the vessel state equation to obtain the controlled vessel state equation, expressed as: T k+1 = GT k + BU k + FW k Among them, T k ∈R n represents the state of the controlled vessel; U k ∈R p represents the output variable of the controller; S k ∈R q represents the measurable output of the controlled vessel; W k ∈R o represents the system interference signal; G, B, L, F, C u are matrices of appropriate dimensions; the linearization transformation module transmits the state equation of the controlled vessel and S k to the full - order state observer; The full-order state observer is used to calculate the state observation value of the controlled vessel. The full-order state observer is as shown in the following formula: Among them, represents the observed value of the state of the controlled vessel; E is the state gain matrix of this full-order state observer; the full-order state observer transmits to the vessel state decoupling module; The vessel state decoupling module is used to decouple the controlled vessel state equation after linearization; let η k =[x k y k z k φ k θ k ψ k T represent the state of the fleet cooperative control system, where x k represents the translational variable along the x n axis in the north-east coordinate system, y k represents the translational variable along the y n axis in the north-east coordinate system, z k represents the translational variable along the z n axis in the north-east coordinate system, φ k represents the rotational angle along the x b axis in the hull coordinate system, θ k represents the rotational angle along the y b axis in the hull coordinate system, ψ k represents the rotational angle along the z b axis in the hull coordinate system; let H represent a non-singular matrix, then we get:​ Among them, is the transformation matrix of G; G s is the separated system matrix corresponding to the state of the fleet cooperative control system; G v is the system matrix corresponding to the states of other controlled vessels; Define: B = H -1 [B s B d ​ F = H -1 [F s F d ​ Among them, represents the state value other than the state of the fleet collaborative control system; is the control input variable corresponding to the state η of the fleet collaborative control system k ; are the remaining control input variables, is the disturbance variable corresponding to the state η of the fleet collaborative control system k ; represents the remaining disturbance variables, B s 、B d 、F d and F s are the corresponding matrices; represents the state observation value obtained through the state observer of the fleet collaborative control system; Then the state equation of the fleet collaborative control system is obtained: The vessel status separator transmits the state equation of the fleet cooperative control system and the fleet cooperative control system state η k to the quantizer.

3. The state observer for a fleet collaborative control system according to claim 2, characterized in that: The quantization method of the quantizer adopts uniform quantization, and the number of quantization levels is m.

4. The state observer for a fleet collaborative control system according to claim 3, characterized in that: The source coding is encoded by using a binary equal-length coding method, and the codeword length is L; the length L of the codeword C is calculated by the following formula: k of the length L: L = 6 log 2 m Channel coding is performed using a binary (N, L) block code coding method, where N ∈ Z is the codeword D after channel coding k and the codeword length of 5. The state observer for a fleet collaborative control system according to claim 4, characterized in that: The system state estimator includes a decoding module, a queuing module, a system state calculation module, a system state prediction module, and a vessel state synthesis module; The decoding module is implemented using the maximum a posteriori probability decoding method and is used to obtain the received code R based on the data packet transmitted by the wireless receiver k , and after decoding the received code R k , the codeword is obtained Based on the codeword , channel decoding is performed to obtain the codeword Then, based on the codeword , source decoding is performed to obtain the quantization value of the fleet cooperative control system state Finally, the obtained quantization value is transmitted to the queuing module; the codeword obtained after decoding is: where d i is the i-th available codeword among all the codewords obtained by the encoder for channel encoding of the codeword C k ; p(d i |R k ) represents the probability of d k occurring given the condition of R i ; The queuing module is used to quantify the received system status values for sorting; the queuing module has a time synchronization function, and quantifies the received system status values for numbering and storage, and reorders the system status quantification values with time delay and out-of-order Then, the sorted system status quantification values are sent to the system status calculation module; The system state prediction module is used to calculate the predicted system state value when there is a time delay in the transmission of the system state quantization value and transmit it to the system state calculation module to ensure that the system state calculation module calculates the observed system state value The system state prediction module performs calculations on the predicted system state value The calculation method is as follows: The system status calculation module is used to calculate the system status observation value of the fleet collaborative control system based on the system status quantization value sent by the queuing module and transmit the calculated system status observation value to the vessel status synthesis module; if there is no time delay in the transmission of the system status quantization value, the system status calculation module directly uses the system status quantization value sent by the queuing module as the system status observation value If there is a time delay in the transmission of the system status quantization value, the system status calculation module uses the system status prediction value provided by the system status prediction module as the system status observation value ​ The vessel status synthesis module is used to obtain the status observation values of the fleet cooperative control system from the system status calculation module plus the vessel status information measured by sensors, and further synthesize all the status information of the vessel and provide it to the controller.

6. A state observation method for a fleet collaborative control system, implemented by using the state observer for a fleet collaborative control system according to claim 1, characterized in that: This method includes the following steps: Step 1: Through ship state separation, obtain the ship position and rotation angle state information of the controlled ship, so as to obtain the state equation of the fleet cooperative control system and the state η of the fleet cooperative control system k ; Step 2: Quantify the state η of the fleet collaborative control system k to obtain a quantization value Step 3: Encode the state quantization value of the fleet collaborative control system ; Step 4: Modulate the encoded codeword D k and send it to the wireless communication network Step 5: The wireless communication network transmits the codewords sent by each ship in the fleet to the wireless receivers of each other; Step 6: Receive the signal of the wireless communication network through the wireless receiver, convert it into a data packet and send it to the system state estimator; Step 7: Calculate the system state observation value through the system state estimator, and calculate the state information of the controlled vessel.

7. The state observation method for a fleet collaborative control system according to claim 6, characterized in that: The specific method of step 1 is as follows: Step 1.1: Obtain the measurable output value of the controlled vessel from the sensor, and perform periodic sampling and analog-to-digital conversion on the measurable output value; Step 1.2: Linearize the vessel state equation to obtain the controlled vessel state equation, expressed as: T k+1 = GT k + BU k + FW k S k = LT k U k = C u S k where, T k ∈R n represents the state of the controlled vessel; U k ∈R p represents the output variable of the controller; S k ∈R q represents the measurable output of the controlled vessel; W k ∈R o represents the system disturbance signal; G, B, L, F, C u are matrices of appropriate dimensions; Step 1.3: Based on the state equation of the controlled vessel in Step 1.2 and S k , calculate the state observation value of the controlled vessel through a full-order state observer as shown in the following equation: Among them, represents the observed value of the state of the controlled vessel; E is the state gain matrix of this full-order state observer; Step 1.4: Decouple the controlled vessel state equation after linearization to obtain the state η of the fleet cooperative control system k ; The specific method is as follows: Let η k = [x k y k z k φ k θ k ψ k T represent the state of the fleet cooperative control system, where x k represents the translational variable along the x n axis in the north-east coordinate system, y k represents the translational variable along the y n axis in the north-east coordinate system, z k represents the translational variable along the z n axis in the north-east coordinate system, φ k represents the rotational angle along the x b axis in the hull coordinate system, θ k represents the rotational angle along the y b axis in the hull coordinate system, ψ k represents the rotational angle along the z b axis in the hull coordinate system; Let H represent a non-singular matrix, then we get:​ Among them, is the transformation matrix of G; G s is the system matrix separated out corresponding to the state of the fleet cooperative control system; G v is the system matrix corresponding to the states of other controlled vessels; Define: B = H -1 [B s B d ​ F = H -1 [F s F d ​ Among them, represents the state value other than the state of the fleet cooperative control system; is the control input variable corresponding to the state η of the fleet cooperative control system k ; is the remaining control input variables, is the disturbance variable corresponding to the state η of the fleet cooperative control system k ; represents the remaining disturbance variables, B s 、B d 、F d and F s are the corresponding matrices; represents the state observation value obtained through the state observer of the fleet cooperative control system; Then the state equation of the fleet collaborative control system is obtained:

8. The state observation method for a fleet collaborative control system according to claim 7, characterized in that: The quantization method in step 2 adopts uniform quantization, and the number of quantization levels is m.

9. The state observation method for a fleet collaborative control system according to claim 8, characterized in that: The specific method of the said step 3 is as follows: Step 3.1: Perform source coding on the quantization value to obtain the codeword C k ; The source coding method uses a binary equal-length coding method, and the codeword length is L; Calculate the codeword C k length L through the following formula: L = 6 log 2 m Step 3.2: Perform channel coding on the codeword C k to obtain the codeword D after channel coding k ; The channel coding method uses a binary (N, L) block code coding method, where N ∈ Z is the codeword length of the codeword D k after channel coding.

10. The method for observing the state of the fleet collaborative control system according to claim 9, characterized in that: The specific method of the said step 7 is as follows: Step 7.1: Obtain the received code R based on the data packet transmitted by the wireless receiver k , and the codeword obtained after decoding it is as follows: where d i is the i-th available codeword among all the codewords obtained by the encoder through channel encoding of the codeword C k ; p(d i |R k ) represents the probability of d k occurring under the condition of a given R i ; Step 7.2: Based on the codeword obtained after decoding perform channel decoding to obtain a codeword Step 7.3: Based on the codeword perform source decoding to obtain the quantization value of the fleet cooperative control system state Step 7.4: Quantize the received system status values number and store them, and reorder the system status quantization values with time delay and out-of-order Step 7.5: Based on the system state quantization values with the re - adjusted order Calculate the state observation value of the fleet collaborative control system The specific method is as follows: If there is no time delay in the transmission of the system state quantization value, directly use the system state quantization value with the reordered sequence in step 7.4 as the system state observation value If there is a time delay in the transmission of the system state quantization value, the predicted system state value is used as the observed system state value The predicted system state value The calculation method is as follows: Let θ represent whether there is a delay; when there is a time delay in the transmission of the system state quantization value, define θ = 1; when there is no time delay in the transmission of the system state quantization value, define θ = 0; then the state observation value of the fleet cooperative control system is calculated as follows: Step 7.6: Add the state observation value of the fleet collaborative control system obtained in Step 7.5 to the vessel state information measured by the sensor, further synthesize all the state information of the vessel, and provide it to the controller.

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