The present invention relates to a method and system for operating a safety-critical device over a non-secure communication network, and for providing reliable disengagement of ongoing operations of the device.
Secure operations of safety-critical devices are vital. For remote controlled operations several measures are standardized and required to operate safety-critical devices. This is especially the case in the defense industry where malfunctioning weapons may have fatal consequences. This industry is moving towards standardized platforms and infrastructures for safe operation of safety-critical devices. In these platforms all systems are required to interoperate over packet-based networks. The operator positions become multipurpose operator positions shared between several systems. The interface between the system and the operator positions thus changes.
The applicant has previously developed a solution where safety-critical operations at a remote location are controlled from a local location via Control Panel Interfaces (CPI) at each location. The solution is described in U.S. Pat. No. 10,063,552 B2, which is hereby included as a reference.
The described solution provides a secure way of enabling and controlling, at a near location, operations of a safety-critical device located at a remote location.
The basic principle of the solution is illustrated in
The upper part of
The system comprises a first operating input device 110 to be operated at the near location by an operator providing a first barrier control signal 112. The system further comprises a second operating input device 120 to be operated at the near location by an operator, providing a second barrier control signal 122.
The operating input device 110, 120 may as an example be a weapon fire control device or a weapon movement control device.
The first 110 and second 120 operating input devices may be arranged to be operated by the same operator or by different operators.
The first and second barrier control signals 112, 122 are communicatively connected to a near end of a secure communication tunnel through a non-secure communication network 140.
A remote end of the secure communication tunnel is communicatively connected to an activating input 152 of a first barrier circuit 150, and to an activating input 162 of a second barrier circuit 160.
The first 150 and second 160 barrier circuits are configured to enable operation of the safety-critical device 180 when both the first 150 and second 160 barrier circuits are activated.
Advantageously, separate hardware circuits are used for implementing the first 150 and second 160 barrier circuits.
The system may further be configured for operating a plurality of safety-critical devices, located at the remote location. The system may then comprise a first multiplexer which multiplexes a plurality of first barrier control signals onto the secure communication tunnel through the non-secure communication network 140. The system may further comprise a second multiplexer, multiplexing a plurality of second barrier control signals onto the secure communication tunnel through the non-secure communication network. The first barrier circuit 150 comprises a first demultiplexer, and the second barrier circuit 160 comprises a second demultiplexer. More details of these features are described in the reference U.S. Pat. No. 10,063,552 B2.
The non-secure communication network 140 may be a packet-based communication network, such as an Internet Protocol (IP) network. The secure communication tunnel may be an IPsec tunnel for the first barrier control signals and the second barrier control signals. The IPsec tunnel may be configured in an integrity only mode, where IPsec receivers authenticate barrier control signals sent by IPsec transmitters to ensure that the data has not been altered during transmission. The barrier circuits may further be configured with a configurable or fixed IP addressing scheme. The configurable scheme may by a dynamic scheme. By using fixed IP addressing higher safety is achieved.
The communication through the secure communication tunnel may employ a protocol which includes timestamping of data. Such aspects are described in the reference U.S. Pat. No. 10,063,552 B2.
In a particular aspect, an operating input device may include a video session information device, and the safety-critical device may be a video confirmation device. In this aspect, the system may further comprise a video distribution device. The video distributing device is arranged to provide a video signal which is transferred through the non-secure communication network and displayed on a display screen at the near end. Further, the video session information device may be configured to derive video session information from the video signal and transfer the video session information through the secure communication tunnel. Also. the video confirmation device may be configured to confirm the authenticity of the video signal transferred through the non-secure communication network. These aspects of a video session information device have been explained in closer detail in reference U.S. Pat. No. 10,063,552 B2.
When distributing data requiring high bandwidth, such as video, stable and high-quality radio communication is not guaranteed, and signal transmission will have a relatively short range compared to radio communication with low bandwidth.
Signal transmission for performing safety-critical operations such as controlling of movements and firing of a weapon station at a remote location will not require high bandwidth. This can thus be performed through each HW barrier while video can be transferred via different channels.
Authorization to proceed (ATP) in relation to weapon systems using Artificial Intelligence (AI) is linked to ethical principles, and the possibility that a person can monitor and deactivate misbehaving AI systems is an absolute requirement.
The Department of Defense (DoD) in the United States has recommended a set of guiding principles for operating weapon systems with different levels of autonomy. One of these principles is that the system must be governable i.e. that the design of AI capabilities shall fulfill their intended functions while possessing the ability to detect and avoid unintended consequences, and the ability to disengage or deactivate deployed systems that demonstrate unintended behavior.
The operational levels are defined as:
For scenarios involving robotic combat vehicles, authorization to proceed is given by one or more operators. It is vital that there is fail-safe way of stopping initiated operations. This is especially the case for scenarios, where the initiated operations are performed by Artificial Intelligence (AI) capabilities of a device at a remote location.
There is thus a need for a solution which may be used for systems to transport safety barriers and signaling over IP/Ethernet networks and thus to provide an Authorization to proceed (ATP), i.e. to disengage safety-critical devices utilizing available radios.
To meet the recommended principles, a device should be fieldable and it should have the following characteristics:
A fieldable solution should further have the following characteristics:
For weapon station installations, it would be beneficial to enable the use of the ATP solutions in cases like UGVs as explained above but also in stationary installations where:
Examples of the above are ships with weapon enabled from the bridge or a base camp with weapon enabled from a supervisor position. For these cases the ATP function is today generally hardwired. With the present invention, it can be networked to enable larger distances with more robust installations, e.g. without using dedicated copper wiring for communication.
The present invention can be applied for all the above listed scenarios, and to different kinds of safety-critical devices safely controlled via a non-secure network.
The solution is called an E-stop and is considered to be similar to ATP with regards to safety but is operating differently. In the ATP solution, a user enables an operation, and in the E-stop solution a user disables an operation.
The solution provides a generalized solution with a safe and secure way of disengaging or deactivating deployed systems.
The solution provides a method and system which may utilize aspects of already existing, hard-wired solutions, fulfil relevant safety requirements, provide a secure, tamper proof and supervised connection, make use of standard protocols and networking elements, and which can be dynamically changed according to needs.
The solution can be applied to available radio communication devices to provide sufficient range to provide a fieldable solution for safety-critical devices operated according to the principle above.
The invention relates to a method and system for operating a safety-critical device over a non-secure communication network, and for providing reliable disengagement of ongoing operations of the device.
The system comprises:
The system further comprises:
In one embodiment, the system further comprises a light source connected to the first and the second hardware safety barriers of the first control panel for indicating status of the safety-critical device. This is preferably one or more LEDs capable of displaying different colors, where for instance green indicates that the safety critical device is enabled, while red indicated that the safety-critical device is disabled.
In one embodiment, the system further comprises a software safety barrier with transparent signaling to and from the first and second control panels interfaces. Transparent signaling channels may provide TOP signaling (JAUS messages) for RCV/UGV mobility solutions or other protocols.
In one embodiment of the system, the first and second control panels interfaces comprise identical hardware, where the first control panel interface is operated as a client, while the second control panel interface is operated as a server. How they are operating is controlled by SW running on each control panel interface.
Further features of the system are defined in the claims.
The invention is further defined by a method comprises:
In one embodiment, the method comprises connecting a light source to the first and the second hardware safety barriers of the first control panel interface for indicating status of the safety-critical device.
In one embodiment of the method, the state of the switch is continuously signaled from the first control panel interface to the second control panel interface and it is continuously verified that the state of the switch corresponds to the Hi- and Lo-signals received on the second hardware safety barriers of the second control panel interface.
In one embodiment of the method, the safety-critical device is disabled when communication between the first and second control panel interfaces is lost, thereby returning the safety-critical device to a default safe state.
Further features of the method are defined in the claims.
As mentioned in the background section above, there is a need for a solution which may be used for systems to transport safety barriers and signaling over IP/Ethernet networks and to provide an “Authorization to proceed” (ATP) for disengaging safety-critical devices utilizing available radios.
The system comprises a first control panel interface 200 and one or more operating connected input devices 210, 220 at a near location. The input devices may for instance be a weapon fire control device and a weapon movement control device. In the figure, input device 210 controls non-safety critical functions, while input device 220 controls safety-critical functions.
The system is adapted for transmitting control signals to the safety-critical device 260 at a remote location, the first control panel interface 200 comprises hardware barrier communication means 206 and at least a first and a second hardware safety barrier 202, 204, each with safety barrier interfaces. The figure illustrates an example where operating input device 220 in connected to the first and second hardware barriers 202, 204. The first and a second hardware safety barriers 202, 204 are further connected to the hardware barrier communication means 206 for safe communication through the non-secure network 240.
The first control panel interface 200 further comprises communication means 205 for transferring signals from input device 210 controlling non-safety critical function of the safety-critical device 260.
The non-secure communication network 240 may be a packet-based communication network, such as an Internet Protocol (IP) network.
The system further comprises a second control panel interface 250, connected to the safety-critical device 260 at the remote location, and which is adapted for receiving control signals from the first control panel interface 200. The second control panel interface 250 comprises hardware barrier communication means 256 and at least a first and a second hardware safety barrier 252, 254, each with safety barrier interfaces connected to the hardware barrier communication means 256 for communication through the non-secure network 240.
The second control panel interface 250 further comprises communication means 255 for transferring signals to and from input device 210 controlling non-safety critical function of the safety-critical device 260.
The system further comprises a switch 215, connected to the first and second hardware safety barriers 202, 204 of the first control panel interface 200, controlling Hi- and Lo-signal inputs on the hardware safety barriers, such that a Hi-signal is input on the first hardware safety barrier 202 and a Lo-signal is input on the second hardware safety barrier 204 and vice versa for respectively enabling and disengaging operation of the safety-critical device 260.
The operational levels, i.e. levels of autonomy, where the invention can be applied, for a safety-critical device, such as for instance for the RWS and RCV, includes all levels 1 to 5 listed in the background section above.
The solution according to the present invention has two different setups, one for level 1 to 3, and one for all levels, i.e. 1 to 5.
Level 1 to 3 requires a high bandwidth radio for closed loop operator control, while level 4 and 5 does not require the same bandwidth and should make use of low bandwidth radios with high availability/range.
These levels are in line with the different levels described in the background section.
The transparent signaling channels may provide TOP signaling (Joint Architecture of Unmanned Systems, JAUS messages) for RCV/UGV mobility solutions or other protocols.
The solution according to the present invention has the following characteristics and advantages:
The solution provides Multi-Client functionality. Through the client management interface illustrated in
All clients in the server arbitration group can all arbitrate for connectivity to the server. The arbitration is fast (<100 msec), activated through io or signaling. The arbitration is based on priority of the allocated role of the client. The system can support many clients and servers in the same network.
The clients are initially, when joining the arbitration group, in the monitoring state. In this state the client is not connect and cannot send/receive on the signaling channels or HW barriers, i.e. all are safe. The client does however receive status information from the server, e.g. which client is connected to the server. If the client is granted connectivity it is in the connected state. In the connected state the signaling and barrier transfer services are provided.
The solution further provides Multi-Server functionality where the servers announce their presence in the network through standard protocols like SAP/SDP distributed in multicast groups. All clients in the network monitors the announcements and builds a list of available servers. The list of servers is made available on the management interface of the client.
The client will at power up belong to a default server but through the management interface of the client the server to connect to can be selected. One server can be connected to at most one client, and one client can be connected to one server.
According to one embodiment of the invention, the system for operating a safety-critical device 260 further comprising a light source 217 as illustrated in
The table below illustrates the different possible situations and corresponding light indications.
The diagnostic information, i.e. the switch positions, is signaled to the server side, i.e. to the second control panel interface 250. The SW on the server side reads the state of the transferred information and verifies the correct state of the HW barrier. If a correspondence is verified, the signal is let through to the output.
The ATP switch 215 in this scenario uses two HW barriers to transfer the Hi- and LO-signal side of the ATP switch 215, and in addition each of the HW barriers has diagnostic signals to verify the correct information transfer where the diagnostic information is transferred on a third path.
The actual state of the server output, i.e. the second control panel interface 250, is then fed back as inputs on the server to provide the reverse path back to the operator for operator confirmation regarding the state of the ATP function. All the signals are multiplexed into an IPsec tunnel for an integrity verified transmission. This solution provides both diversity on multiple HW barriers and diagnostics on each barrier.
The server SW can support a local emergency stop as an addition to the ATP/E-Stop connected to the client and can further support multiple simultaneous barrier signals with diagnostics as shown.
The ATP function may be combined with transparent signaling channels as shown in Error! Reference source not found.
The current inventive solutions for ATP/E-stop over Ethernet/IP are based on solutions where a SW architecture is “made safe”. The SW is designed for high certified integrity levels, typically SIL3, IEC 61508 with safety protocols added on top of a standard transmission protocol set. Examples of this are:
All identified alternative solutions are based on SW developed with a formalized process and well-defined architecture to establish a safe solution. These types of solutions do not provide a verifiable diversity in the same way as the proposed solution. Neither do they provide the same level of safe operation, SIL 3 according to IEC 61508 shall provide a system probability of dangerous failure per hour (PFH) of 10−7-10−8. The proposed ATP/E-stop solution provides a PFH which is above SIL 4.
ATP Authorization to proceed
110—operating input device
112 —first barrier control signal
120—operating input device
122—second barrier control signal
140—communication network
150—first barrier circuit
152—first activating input
160—second barrier circuit
162—second activating input
180—safety critical device
200—first control panel interface
202—first hardware barrier
204—second hardware barrier
205—communication means
206—hardware barrier communication means
210—first input device
215—switch
217—light source
220—second input device
240—non-secure network
242—secure communication tunnel
250—second control panel interface
252—first hardware barrier
254—second hardware barrier
255—communication means
256—hardware barrier communication means
260—safety critical device