Patent Description:
Controller area network (CAN) is a data communication protocol that is generally used for broadcasting sensor data and/or control data on two-wire interconnections between different parts of an electronic control system. A CAN bus is structured to have a high-line, a low-line, and one or more nodes, with each node being coupled to both the high-line and the low-line. Proper functioning of the CAN bus necessitates that both physical endpoints of the CAN bus be capped with terminating resistances. Generally, this is facilitated by applying a terminating resistance to a very first node of the CAN bus and another terminating resistance to a very last node of the CAN bus, with such nodes being referred to as "terminating nodes. " Terminating resistances are not applied to other nodes that are between the terminating nodes, and so such other nodes are referred to as "non-terminating nodes. " When an electronic connection to a terminating node is lost, performance of the CAN bus is negatively affected. Existing techniques for repairing the performance of the CAN bus, such as re-routing or double termination, are not optimal.

Systems and/or techniques that can address one or more of these problems can be desirable. Examples of such systems may be known from <CIT>, <CIT>, <CIT> and <CIT>.

The following presents a summary to provide a basic understanding of one or more embodiments of the invention. In one or more embodiments described herein, devices, systems, computer-implemented methods, apparatus and/or computer program products that can facilitate smart CAN termination are described.

One or more embodiments are now described with reference to the drawings, wherein like referenced numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a more thorough understanding of the one or more embodiments. It is evident, however, in various cases, that the one or more embodiments can be practiced without these specific details.

Controller area network (CAN), including both classical controller area network (Classical CAN) and controller area network flexible data-rate (CAN-FD), is a data communication protocol that is generally used for broadcasting sensor data and/or control data on two-wire interconnections between different parts of an electronic control system. CAN is particularly popular in the automotive field. Specifically, CAN buses can be implemented in a vehicle, so as to communicatively couple various electronic modules (e.g., accelerometer module, fuel sensor module, temperature sensor module, engine control module, door/window module, airbag/safety module, air conditioning module) of the vehicle together.

The physical topology of a CAN bus can include a high-line, a low-line, and a set of nodes, with each node being coupled to both the high-line and the low-line. Moreover, the high-line and the low-line of the CAN bus can together be considered as forming a path that has two physical endpoints, where one of the set of nodes is coupled to both the high-line and the low-line at one of the two physical endpoints, where another of the set of nodes is coupled to both the high-line and the low-line at the other of the two physical endpoints, and where the rest of the set of nodes are coupled to both the high-line and the low-line at various sequential points along the path between the two physical endpoints.

Proper functioning of the CAN bus can require that both of the two physical endpoints be capped with terminating resistances. This can be facilitated by applying a terminating resistance to the node that is placed at and/or near the first physical endpoint (e.g., implementing the terminating resistance in parallel with the node at the first endpoint) and by applying another terminating resistance to the node that is placed at and/or near the second physical endpoint (e.g., again, implementing the terminating resistance in parallel with the node at the second endpoint). Accordingly, the two nodes to which terminating resistances are applied can be referred to as "terminating nodes. " The rest of the set of nodes that are placed in between the terminating nodes can lack terminating resistances, and so such nodes can be referred to as "non-terminating nodes.

When an electronic connection to a terminating node is lost (e.g., such as due to a crash of the terminating node), performance of the CAN bus can be negatively affected. Specifically, the CAN bus can experience significantly degraded signal quality and/or significantly reduced electromagnetic compatibility when one or both of the terminating nodes are lost, which can cause other modules coupled to the CAN bus to stop functioning properly. Existing techniques for repairing the performance of the CAN bus, such as re-routing or double termination, are not optimal. Thus, systems and/or techniques for restoring performance of the CAN bus when one or both terminating nodes are lost can be desirable.

Various embodiments of the invention can address one or more of these technical problems by facilitating smart CAN termination. In particular, various embodiments of the invention can be considered as a computerized tool (e.g., any suitable combination of computer-executable hardware and/or computer-executable software) that can electronically monitor a CAN bus and that can electronically restore performance of the CAN bus when one or both terminating nodes are lost. More specifically, the computerized tool can electronically measure an impedance of the CAN bus, can electronically determine whether one or both terminating nodes are lost based on the impedance, and/or can electronically apply terminating resistances to one or more non-terminating nodes based on the determination, such that the one or more non-terminating nodes can now function as terminating nodes. In other words, the computerized tool can detect when a terminating node of the CAN bus is lost, and the computerized tool can replace the lost terminating node by converting a nearby one of the remaining nodes of the CAN bus from a non-terminating state to a terminating state. So, when a terminating node is lost, the computerized tool can ensure that another terminating node is created to take its place, with the result being that the CAN bus is properly terminated. Accordingly, when the performance of the CAN bus suffers due to loss of a terminating node, the computerized tool can rectify the performance of the CAN bus by changing one of the remaining nodes to a terminating node.

In various embodiments, the computerized tool described herein can comprise a sensor component, a comparison component, and/or a termination component.

In various aspects, as mentioned above, a CAN bus (e.g., a Classical CAN bus, a CAN-FD bus) can comprise a high-line, a low-line, and/or a set of nodes that are each coupled to both the high-line and the low-line. In various instances, the set of nodes can comprise three or more nodes. In various cases, each node of the set of nodes can be any suitable computerized module that can receive signals from and/or transmit signals to the CAN bus.

In various cases, each node of the set of nodes can correspond to one or more switchable terminating resistors. More specifically, each node can be coupled in parallel with its corresponding switchable terminating resistor. In various aspects, a switchable terminating resistor can comprise one or more resistors that are coupled to the high-line and the low-line of the CAN bus in any suitable fashion/arrangement by one or more switches. For any given node, if the one or more switches of the switchable terminating resistor that corresponds to the given node are closed, the one or more resistors that correspond to the switchable terminating resistor can be electrically active (e.g., can receive electric signals/current from the high-line and/or the low-line of the CAN bus). If the one or more resistors of the switchable terminating resistor corresponding to the given node are electrically active, the given node can be considered to be in a terminating state. On the other hand, for any given node, if the one or more switches of the switchable terminating resistor that corresponds to that given node are open, the one or more resistors that correspond to the switchable terminating resistor can be electrically inactive (e.g., can fail to receive electric signals/current from the high-line and/or the low-line of the CAN bus). If the one or more resistors of the switchable terminating resistor corresponding to the given node are electrically inactive, the given node can be considered to be in a non-terminating state. Accordingly, each of the set of nodes can be selectably terminable. For instance, any node can be converted from a non-terminating state to a terminating state by closing the one or more switches of the switchable terminating resistor that corresponds to that node. Conversely, any node can be converted from a terminating state to a non-terminating state by opening the one or more switches of the switchable terminating resistor that corresponds to that node.

In various embodiments, the sensor component of the computerized tool can electronically measure an impedance of the CAN bus. More specifically, the sensor component can comprise any suitable impedance sensor that can be electrically coupled to and/or otherwise integrated with the CAN bus. Accordingly, the sensor component can, via the impedance sensor, measure, detect, and/or otherwise quantify the impedance exhibited by the CAN bus at any suitable moment in time and/or over any suitable timespan. Those having ordinary skill in the art will appreciate that the impedance sensor can implement any suitable impedance-measuring techniques and/or impedance-measuring circuitry. For instance, the impedance sensor can, in various cases, be any suitable form of an impedance analyzer and/or a multimeter.

In various embodiments, the comparison component of the computerized tool can electronically compare the impedance as measured by the sensor component to any suitable thresholds, so as to determine whether and/or how many terminating nodes of the CAN bus are lost. More specifically, because each of the set of nodes can be considered as being coupled in parallel with each other, the two terminating nodes can likewise be in parallel with each other. Thus, the comparison component can leverage the rule governing combination of parallel resistances to determine whether and/or how many terminating nodes are lost. In various aspects, due to how parallel resistances combine (e.g., the reciprocal of the sum of the reciprocals of two parallel resistances is lesser than each of the two parallel resistances individually), the impedance of the CAN bus can increase if one of the two terminating nodes is lost. By the same logic, the impedance of the CAN bus can increase even further if both of the two terminating nodes are lost. Accordingly, the comparison component can leverage two predetermined thresholds to determine whether and/or how many terminating nodes of the CAN bus are lost.

For instance, the comparison component can have any suitable form of electronic access to a double-loss threshold and to a single-loss threshold. In various cases, the double-loss threshold can represent a minimum impedance value of the CAN bus that occurs when both of the terminating nodes are lost. Similarly, the single-loss threshold can represent a minimum impedance value of the CAN bus that occurs when one of the two terminating nodes is lost. Again, due to the nature of parallel resistors, the double-loss threshold can be greater than the single-loss threshold. Thus, the comparison component can, in various instances, compare the impedance measured by the sensor component to the double-loss threshold. If the impedance is greater than the double-loss threshold, the comparison component can conclude and/or determine that both terminating nodes of the CAN bus are lost. If the impedance is not greater than the double-loss threshold, the comparison component can compare the impedance to the single-loss threshold. If the impedance is greater than the single-loss threshold, the comparison component can conclude and/or determine that one of the two-terminating nodes is lost. If the impedance is not greater than the single-loss threshold, the comparison component can conclude and/or determine that neither of the two terminating nodes is lost.

Those having ordinary skill in the art will appreciate that the magnitudes of the double-loss threshold and/or the single-loss threshold can depend upon the characteristics and/or properties of the CAN bus (e.g., can depend upon the resistance values of the switchable terminating resistor of each node of the CAN bus and/or upon other electrical components/loads coupled to the CAN bus). Accordingly, those having ordinary skill in the art will understand that the double-loss threshold and/or the single-loss threshold can be determined experimentally and/or analytically based on the CAN bus.

In various embodiments, the termination component of the computerized tool can electronically convert at least one node of the CAN bus from a non-terminating state to a terminating state, based on the conclusion and/or determination of the comparison component. In various aspects, as mentioned above, each node of the CAN bus can have a corresponding switchable terminating resistor. In various instances, the termination component can be coupled, via any suitable control-logic-circuitry, to the switchable terminating resistor of each node. Accordingly, for any given node, the termination component can, in various aspects, transmit a control signal to the switchable terminating resistor of the given node, which can cause the one or more switches of the switchable terminating resistor to open or close. If the one or more switches of the switchable terminating resistor are open, the switchable terminating resistor can be electrically inactive, and so the given node can be in a non-terminating state. On the other hand, if the one or more switches are closed, the switchable terminating resistor can be electrically active, and so the given node can be in a terminating state. Thus, if the control signal causes the one or more switches to change from open to closed, the control signal can be considered as converting the given node from a non-terminating state to a terminating state. Conversely, if the control signal causes the one or more switches to change from closed to open, the control signal can be considered as converting the given node from a terminating state to a non-terminating state. In this way, the termination component can convert any node of the CAN bus from a non-terminating state to a terminating state, and/or vice versa.

In various aspects, if the comparison component determines that both terminating nodes of the CAN bus are lost, the termination component can electronically transmit control signals to the switchable terminating resistors of two of the remaining nodes in the CAN bus. In other words, when both terminating nodes of the CAN bus are lost, the termination component can replace those two lost terminating nodes with two of the remaining nodes, by converting the two of the remaining nodes to terminating states. More specifically, the set of nodes of the CAN bus can be ordered and/or indexed in any suitable fashion, with one of the two terminating nodes representing one end of such ordering/indexing and with the other of the two terminating nodes representing the other end of such ordering/indexing. In various instances, if the comparison component concludes that both terminating nodes are lost, the termination component can identify the two of the remaining nodes that are respectively adjacent and/or otherwise nearest to the two lost terminating nodes, according to the ordering/indexing. Once those two remaining nodes are identified, the termination component can transmit control signals to the switchable terminating resistors of those two remaining nodes, thereby converting them to terminating states. Thus, those two remaining nodes can now be considered as two new terminating nodes. As a result, the CAN bus can again have two terminating nodes, which can restore proper performance of the CAN bus.

In various instances, if the comparison component instead determines that only one terminating node of the CAN bus is lost, the termination component can electronically transmit control signals to the switchable terminating resistor of one of the remaining nodes in the CAN bus. In other words, when one terminating node of the CAN bus is lost, the termination component can replace that one lost terminating node with one of the remaining nodes, by converting the one of the remaining nodes to a terminating state. More specifically, just as above, the set of nodes of the CAN bus can be ordered and/or indexed in any suitable fashion, with one of the two terminating nodes representing one end of such ordering/indexing and with the other of the two terminating nodes representing the other end of such ordering/indexing. In various instances, if the comparison component concludes that one terminating node is lost, the termination component can identify which terminating node is lost. For example, the termination component can attempt to communicate with both terminating nodes, and whichever terminating node fails to respond can be considered as lost. In various cases, the termination component can identify a remaining node that is adjacent and/or otherwise nearest to the lost terminating node, according to the ordering/indexing. Once that remaining node is identified, the termination component can transmit control signals to the switchable terminating resistor of that remaining node, thereby converting it to a terminating state. Thus, that remaining node can now be considered as a new terminating node. As a result, the CAN bus can again have two terminating nodes, which can restore proper performance of the CAN bus.

To help clarify some of the above discussion, consider the following example. Suppose that a CAN bus comprises a high-line, a low-line, and five nodes: node <NUM>, node <NUM>, node <NUM>, node <NUM>, and node <NUM>, each corresponding to a switchable terminating resistor. Furthermore, suppose that the five nodes are ordered in the CAN bus according to their indexes: that is, node <NUM> is located at one endpoint of the CAN bus, node <NUM> is located at the other endpoint of the CAN bus, node <NUM> is adjacent to node <NUM> and node <NUM>, node <NUM> is adjacent to node <NUM> and node <NUM>, and node <NUM> is adjacent to node <NUM> and node <NUM>. Because node <NUM> and node <NUM> are located at the endpoints of the CAN bus, they can initially be the two terminating nodes. That is, node <NUM> and node <NUM> can be in terminating states (e.g., the switches of the switchable terminating resistors of node <NUM> and node <NUM> can be closed), while nodes <NUM>-<NUM> can be in non-terminating states (e.g., the switches of the switchable terminating resistors of nodes <NUM>-<NUM> can be open).

In various aspects, the sensor component of the computerized tool can, via the impedance sensor, measure the impedance of the CAN bus. In various instances, the comparison component of the computerized tool can compare the impedance to the double-loss threshold. If the impedance is greater than the double-loss threshold, the comparison component can conclude that both node <NUM> and node <NUM> are lost. In other words, the comparison component can determine that node <NUM> and node <NUM> cannot be communicated and/or otherwise interacted with via the CAN bus. At such point, the CAN bus can be considered as not properly terminated, which can degrade the performance of the CAN bus. Accordingly, the termination component of the computerized tool can identify two of the remaining nodes <NUM>-<NUM> that are respectively adjacent to node <NUM> and node <NUM>. Here, node <NUM> is a remaining (e.g., not lost) node that is adjacent to node <NUM>, and node <NUM> is a remaining node that is adjacent to node <NUM>. Thus, the termination component can transmit a control signal to the switchable terminating resistor of node <NUM>, thereby causing node <NUM> to change from a non-terminating state to a terminating state. Similarly, the termination component can transmit another control signal to the switchable terminating resistor of node <NUM>, thereby causing node <NUM> to change from a non-terminating state to a terminating state. At such point, the CAN bus can be considered as properly terminated, with node <NUM> and node <NUM> functioning as the new terminating nodes. Thus, the performance of the CAN bus can be restored, notwithstanding the loss of node <NUM> and node <NUM>.

If the impedance is not greater than the double-loss threshold, the comparison component can compare the impedance to the single-loss threshold. If the impedance is greater than the single-loss threshold, the comparison component can conclude that only one of node <NUM> and node <NUM> are lost. At such point, the CAN bus can be considered as not properly terminated, which can degrade the performance of the CAN bus. Accordingly, the termination component of the computerized tool can identify which of node <NUM> and node <NUM> is lost. For instance, the termination component can attempt to electronically communicate with both node <NUM> and node <NUM>. If node <NUM> properly responds while node <NUM> fails to properly respond, it can be inferred that node <NUM> is lost. Conversely, if node <NUM> fails to properly respond while node <NUM> properly responds, it can be inferred that node <NUM> is lost. Once the lost terminating node is identified, the termination component can identify one of the remaining nodes <NUM>-<NUM> that is adjacent to the lost terminating node. If node <NUM> is lost, node <NUM> is the remaining (e.g., not lost) node that is adjacent to the lost terminating node. On the other hand, if node <NUM> is lost, node <NUM> is the remaining node that is adjacent to the lost terminating node. In any case, the termination component can transmit a control signal to the switchable terminating resistor of the remaining node that is adjacent to the lost terminating node, thereby causing that remaining node to change from a non-terminating state to a terminating state. At such point, the CAN bus can be considered as properly terminated, with the remaining node that is adjacent to the lost terminating node functioning as a new terminating node. For instance, if node <NUM> is lost, node <NUM> can be converted to a terminating state, meaning that node <NUM> can function as a new terminating node. Conversely, if node <NUM> is lost, node <NUM> can be converted to a terminating state, meaning that node <NUM> can function as a new terminating node. In any case, the performance of the CAN bus can be restored, notwithstanding the loss of one of the terminating nodes.

Accordingly, a computerized tool as described herein can periodically monitor the impedance of a CAN bus to detect loss of one or both terminating nodes of the CAN bus. If the computerized tool determines that one or both of the terminating nodes are lost, the computerized tool can convert one or more of the remaining nodes of the CAN bus from non-terminating states to terminating states. Thus, the computerized tool can dynamically keep the CAN bus properly terminated, even when one or both terminating nodes of the CAN bus are lost due to system crashes.

Various embodiments of the invention can be employed to use hardware and/or software to solve problems that are highly technical in nature (e.g., to facilitate smart CAN termination), that are not abstract and that cannot be performed as a set of mental acts by a human. Further, some of the processes performed can be performed by a specialized computer. Specifically, such processes can include: measuring, by a device operatively coupled to a processor, an impedance of a controller area network (CAN) bus; and converting, by the device, at least one node of the CAN bus from a non-terminating state to a terminating state, based on the impedance. According to the present invention, the at least one node of the CAN bus is associated with a switchable terminating resistor having one or more switches, wherein the at least one node is in the non-terminating state when the one or more switches are open, and wherein the at least one node is in the terminating state when the one or more switches are closed. Such defined tasks are not performed manually by humans. Moreover, neither the human mind nor a human with pen and paper can electronically measure an electrical impedance of a CAN bus, and/or electronically change a termination status of a node of the CAN bus based on the measured impedance. Instead, various embodiments of the invention are inherently and inextricably tied to computer technology and cannot be implemented outside of a computing environment (e.g., a CAN bus is a specific circuit topology that is inherently related to computing devices; thus, a computerized tool that monitors the CAN bus for lost terminating nodes and accordingly converts non-terminating nodes to terminating nodes so as to preserve the performance of the CAN bus can exist only in a computerized environment and cannot be implemented in any sensible way without computers).

In various instances, embodiments of the invention can integrate into a practical application the disclosed teachings regarding smart CAN termination. Indeed, as described herein, various embodiments of the invention, which can take the form of systems and/or computer-implemented methods, can be considered as a computerized tool that can electronically measure the impedance of a CAN bus, that can electronically determine whether and/or how many terminating nodes of the CAN bus are lost based on the impedance, and/or that can electronically transmit control signals to switchable terminating resistors corresponding to one or more remaining nodes of the CAN bus, so as to convert the one or more remaining nodes from non-terminating states to terminating states. In other words, such a computerized tool can help to ensure that a CAN bus is properly terminated during operation, even if the CAN bus experiences a system crash that causes one or both of its existing terminating nodes to be lost. Without the computerized tool, the performance of a CAN bus that loses one or both terminating nodes would be severely degraded. On the other hand, when the computerized tool is implemented, the performance of a CAN bus that loses one or both terminating nodes can, in various aspects, be restored in real-time. Thus, the computerized tool as described herein can be implemented so as to help a CAN bus overcome the technical problem of lost terminating nodes. That is, the computerized tool can improve the very functioning/performance of a CAN bus, and thus the computerized tool certainly constitutes a concrete and tangible technical improvement in the field of controller area networks.

Furthermore, various embodiments of the invention can control tangible, hardware-based, and/or software-based devices based on the disclosed teachings. For example, a CAN bus can be real-world circuit architecture that includes a high-line, a low-line, and a set of nodes, with each node corresponding to a switchable terminating resistor. As explained herein, a switchable terminating resistor can itself be a real-world circuit structure comprising one or more resistors and/or one or more switches that couple the one or more resistors to the high-line and the low-line. When the one or more switches of the switchable terminating resistor of a given node are open, the switchable terminating resistor can be electrically inactive, meaning that the given node can be in a non-terminating state. On the other hand, when the one or more switches of the switchable terminating resistor of the given node are closed, the switchable terminating resistor can be electrically active, meaning that the given node can be in a terminating state. Accordingly, the computerized tool described herein can send real-world control signals to the real-world switchable terminating resistors of any given node, thereby causing that given node to change from a non-terminating state to a terminating state, or vice versa. In any case, such a computerized tool constitutes real-world computer hardware that is interacting with real-world CAN bus circuitry to solve the problem of lost terminating nodes.

<FIG> illustrates a block diagram of an example, system <NUM> that can facilitate smart CAN termination in accordance with one or more embodiments described herein. As shown, a smart CAN bus termination system <NUM> can be electronically integrated, via any suitable wired and/or wireless electronic connection, with a CAN bus <NUM>.

In various embodiments, the CAN bus <NUM> can be a Classical CAN bus, a CAN-FD bus, and/or any other suitable type of CAN bus. More specifically, the CAN bus <NUM> can comprise a high-line, a low-line, and/or a set of nodes <NUM>, with each of the set of nodes <NUM> being coupled between the high-line and the low-line. In various aspects, the set of nodes <NUM> can comprise n nodes, for any suitable positive integer n (e.g., node <NUM> to node n). In various instances, because each of the set of nodes <NUM> can be coupled to both the high-line and the low-line, the set of nodes <NUM> can be considered as being coupled in parallel with each other. Furthermore, in various cases, the high-line and the low-line of the CAN bus <NUM> can form a path, such that the path includes two physical endpoints. In various aspects, node <NUM> of the set of nodes <NUM> can be positioned at and/or near one of the two physical endpoints of the CAN bus <NUM>. Likewise, node n of the set of nodes <NUM> can be positioned at and/or near the other of the two physical endpoints of the CAN bus <NUM>. In various instances, the remainder of the set of nodes <NUM> (e.g., node <NUM> to node n - <NUM>, which are not shown) can be positioned at corresponding points of the CAN bus <NUM> that are between the two physical endpoints (e.g., such that node <NUM> is adjacent to node <NUM>, node <NUM> is adjacent to node <NUM>,. , and node n is adjacent to node n - <NUM>).

In various aspects, each of the set of nodes <NUM> can have, correspond to, and/or otherwise be associated with a switchable terminating resistor. In various instances, a switchable terminating resistor can comprise any suitable number of electrical resistance elements (e.g., resistors having defined resistance values measured in Ohms) that are coupled, in any suitable fashion and/or arrangement via any suitable number of electrical switches, to the high-line and the low-line of the CAN bus <NUM>. In various cases, if the electrical switches of a switchable terminating resistor are open, the switchable terminating resistor can be considered as electrically inactive. That is, the electrical resistance elements of the switchable terminating resistor can be unable to receive current from the high-line and/or low-line of the CAN bus <NUM>. Conversely, in various cases, if the electrical switches of a switchable terminating resistor are closed, the switchable terminating resistor can be considered as electrically active. That is, the electrical resistance elements of the switchable terminating resistor can be able to receive current from the high-line and/or low-line of the CAN bus <NUM>.

As mentioned above, each of the set of nodes <NUM> can have a corresponding switchable terminating resistor (e.g., n nodes, n switchable terminating resistors, one switchable terminating resistor per node). More specifically, each of the set of nodes <NUM> can be coupled in parallel with its corresponding switchable terminating resistor. In various instances, for any given node, if the switchable terminating resistor of the given node is electrically inactive, the given node can be considered as being in a non-terminating state. After all, if the switchable terminating resistor of the given node is electrically inactive, the switchable terminating resistor cannot function so as to apply a terminating resistance to the given node. On the other hand, if the switchable terminating resistor of the given node is electrically active, the given node can be considered as being in a terminating state. After all, if the switchable terminating resistor of the given node is electrically active, the switchable terminating resistor can function so as to apply a terminating resistance to the given node. Thus, each of the set of nodes <NUM> can, in various aspects, be converted from a non-terminating state to a terminating state, and/or vice versa, by controllably closing and/or opening the switches of the switchable terminating resistor that corresponds to the node.

In various instances, because node <NUM> and node n can be positioned at the two physical endpoints of the CAN bus <NUM>, node <NUM> and node n can initially be configured to be in terminating states. Moreover, because the rest of the set of nodes <NUM> (e.g., node <NUM> to node n - <NUM>) can be positioned at locations between the two physical endpoints of the CAN bus <NUM>, the rest of the set of nodes <NUM> can initially be configured to be in non-terminating states. Accordingly, the CAN bus <NUM> can have two terminating nodes, which can mean that the CAN bus <NUM> is properly terminated. In various aspects, it is possible that the CAN bus <NUM> experiences one or more system crashes, which can cause the CAN bus <NUM> to lose electrical connections to one or both of its two terminating nodes. In such case, a terminating node with which electric connection has been lost can be referred to as a lost terminating node. In various instances, if one or both of the two terminating nodes of the CAN bus <NUM> are lost, the performance of the CAN bus <NUM> can be significantly negatively impacted (e.g., signal quality can be degraded). In various aspects, as described herein, the smart CAN bus termination system <NUM> can periodically monitor the CAN bus <NUM> so as to restore the performance of the CAN bus <NUM> if one or both of the terminating nodes are lost.

In various embodiments, the smart CAN bus termination system <NUM> can comprise a processor <NUM> (e.g., computer processing unit, microprocessor) and a computer-readable memory <NUM> that is operably connected to the processor <NUM>. The memory <NUM> can store computer-executable instructions which, upon execution by the processor <NUM>, can cause the processor <NUM> and/or other components of the smart CAN bus termination system <NUM> (e.g., sensor component <NUM>, comparison component <NUM>, termination component <NUM>) to perform one or more acts. In various embodiments, the memory <NUM> can store computer-executable components (e.g., sensor component <NUM>, comparison component <NUM>, termination component <NUM>), and the processor <NUM> can execute the computer-executable components.

In various embodiments, the smart CAN bus termination system <NUM> can comprise a sensor component <NUM>. In various aspects, the sensor component <NUM> can electronically measure an impedance of the CAN bus <NUM>. In various instances, the sensor component <NUM> can measure the impedance by implementing any suitable impedance sensor (e.g., impedance analyzer, multimeter) that can be electronically integrated with the CAN bus <NUM>.

In various embodiments, the smart CAN bus termination system <NUM> can comprise a comparison component <NUM>. In various aspects, the comparison component <NUM> can electronically compare the impedance measured by the sensor component <NUM> to any suitable threshold values, so as to determine whether and/or how many of the terminating nodes of the CAN bus <NUM> are lost. As mentioned above, the terminating nodes of the CAN bus <NUM> can be in parallel with each other. Accordingly, their respective terminating resistances can also be in parallel with each other. Thus, the rule governing how parallel resistances sum together (e.g., reciprocal of the sum of the reciprocals) can be leveraged to determine whether and/or how many of the terminating nodes of the CAN bus <NUM> are lost. More specifically, if both terminating nodes are not lost, the impedance of the CAN bus <NUM> can be expected to be at and/or near a first predetermined value (e.g., which can be based on the properties/characteristics of the CAN bus <NUM>). If one of the terminating nodes is lost, the impedance of the CAN bus <NUM> can be expected to increase to and/or near a second predetermined value (e.g., again, can be based on the properties/characteristics of the CAN bus <NUM>) that is greater than the first predetermined value. Moreover, if both terminating nodes are lost, the impedance of the CAN bus <NUM> can be expected to increase even more to and/or near a third predetermined value (e.g., again, can be based on the properties/characteristics of the CAN bus <NUM>) that is greater than the second predetermined value. Accordingly, the comparison component <NUM> can conclude and/or determine whether and/or how many of the terminating nodes of the CAN bus <NUM> are lost, by comparing the impedance measured by the sensor component <NUM> to the second predetermined value and/or to the third predetermined value (e.g., if the impedance is greater than both the third predetermined value and the second predetermined value, both terminating nodes are lost; if the impedance is less than the third predetermined value and greater than the second predetermined value, only one terminating node is lost; and if the impedance is less than both the third predetermined value and the second predetermined value, no terminating node is lost).

In various embodiments, the smart CAN bus termination system <NUM> can comprise a termination component <NUM>. In various aspects, the termination component <NUM> can electronically transmit control signals to one or more of the set of nodes <NUM>, based on the conclusion/determination produced by the comparison component <NUM>. For instance, if the comparison component <NUM> determines that both terminating nodes of the CAN bus <NUM> are lost, the termination component <NUM> can identify two remaining nodes of the set of nodes <NUM> that are not lost and/or that are respectively adjacent to the two lost terminating nodes. Thus, the termination component can transmit control signals to the switchable terminating resistors of those two remaining nodes, thereby converting those two remaining nodes from non-terminating states to terminating states. As another example, if the comparison component <NUM> determines that only one terminating node of the CAN bus <NUM> is lost, the termination component <NUM> can identify one remaining node of the set of nodes <NUM> that is not lost and/or that is adjacent to the lost terminating node. Accordingly, the termination component can transmit a control signal to the switchable terminating resistor of that one remaining node, thereby converting that one remaining node from a non-terminating state to a terminating state. In any case, based on how many terminating nodes are lost as determined by the comparison component <NUM>, the termination component <NUM> can cause a corresponding number of the rest of the set of nodes <NUM> to enter terminating states, so as to cause the CAN bus <NUM> to be properly terminated.

<FIG> illustrates a block diagram <NUM> of an example, smart CAN bus in accordance with one or more embodiments described herein. In other words, <FIG> depicts an example embodiment of the CAN bus <NUM>.

As shown, the CAN bus <NUM> can comprise a high-line <NUM> and/or a low-line <NUM>, which can be considered as collectively forming a path that defines the CAN bus <NUM>. Note that although <FIG> depicts such path as being straight and/or linear (e.g., from the left side of <FIG> straight to the right side of <FIG>), this is a mere non-limiting example. In various cases, the CAN bus <NUM> can be shaped and/or arranged in any suitable fashion. In various instances, each of the set of nodes <NUM> can be coupled to both the high-line <NUM> and/or the low-line <NUM>, as shown. As mentioned above, the set of nodes <NUM> can comprise n nodes, for any suitable positive integer n. That is, the set of nodes <NUM> can comprise node <NUM> to node n. As shown, the node <NUM> can be positioned and/or located at one physical endpoint of the CAN bus <NUM> (e.g., at a left endpoint of the path formed by the CAN bus <NUM>). Also as shown, the node n can be positioned and/or located at another physical endpoint of the CAN bus <NUM> (e.g., at a right endpoint of the path formed by the CAN bus <NUM>). In various cases, a node j, for any suitable positive integer <NUM> < j < n, can represent an intermediate node that is positioned and/or located at a corresponding point between the node <NUM> and the node n.

In various aspects, each node of the set of nodes <NUM> can be coupled in parallel with a corresponding switchable terminating resistor, where each switchable terminating resistor comprises any suitable number of electrical resistors and/or any suitable number of electrical switches.

For instance, as shown, an electrical resistor <NUM>(<NUM>) and an electrical switch <NUM>(<NUM>) can collectively be considered as a switchable terminating resistor of the node <NUM>. Indeed, as shown, the electrical resistor <NUM>(<NUM>) and the electrical switch <NUM>(<NUM>) can form a series connection that couples the high-line <NUM> to the low-line <NUM>, which series connection is in parallel with the node <NUM>. In various aspects, if the electrical switch <NUM>(<NUM>) is open, electric current from the high-line <NUM> and/or the low-line <NUM> can be unable to flow across the electrical resistor <NUM>(<NUM>). In such case, the switchable terminating resistor collectively formed by the electrical resistor <NUM>(<NUM>) and the electrical switch <NUM>(<NUM>) can be considered as electrically inactive, and the node <NUM> can thus be considered to be in a non-terminating state. In other words, if the electrical switch <NUM>(<NUM>) is open, the electrical resistor <NUM>(<NUM>) can fail to apply a terminating resistance to (e.g., in parallel with) the node <NUM>. On the other hand, if the electrical switch <NUM>(<NUM>) is closed, electric current from the high-line <NUM> and/or the low-line <NUM> can flow across the electrical resistor <NUM>(<NUM>). In such case, the switchable terminating resistor collectively formed by the electrical resistor <NUM>(<NUM>) and the electrical switch <NUM>(<NUM>) can be considered as electrically active, and the node <NUM> can thus be considered to be in a terminating state. In other words, if the electrical switch <NUM>(<NUM>) is closed, the electrical resistor <NUM>(<NUM>) can apply a terminating resistance to (e.g., in parallel with) the node <NUM>.

As another example, as shown, an electrical resistor <NUM>(j) and an electrical switch <NUM>(j) can collectively be considered as a switchable terminating resistor of the node j. Indeed, as shown, the electrical resistor <NUM>(j) and the electrical switch <NUM>(j) can form a series connection that couples the high-line <NUM> to the low-line <NUM>, which series connection is in parallel with the node j. In various aspects, if the electrical switch <NUM>(j) is open, electric current from the high-line <NUM> and/or the low-line <NUM> can be unable to flow across the electrical resistor <NUM>(j). In such case, the switchable terminating resistor collectively formed by the electrical resistor <NUM>(j) and the electrical switch <NUM>(j) can be considered as electrically inactive, and the node j can thus be considered to be in a non-terminating state. That is, if the electrical switch <NUM>(j) is open, the electrical resistor <NUM>(j) can fail to apply a terminating resistance to (e.g., in parallel with) the node j. On the other hand, if the electrical switch <NUM>(j) is closed, electric current from the high-line <NUM> and/or the low-line <NUM> can flow across the electrical resistor <NUM>(j). In such case, the switchable terminating resistor collectively formed by the electrical resistor <NUM>(j) and the electrical switch <NUM>(j) can be considered as electrically active, and the node j can thus be considered to be in a terminating state. That is, if the electrical switch <NUM>(j) is closed, the electrical resistor <NUM>(j) can apply a terminating resistance to (e.g., in parallel with) the node j.

Likewise, as shown, an electrical resistor <NUM>(n) and an electrical switch <NUM>(n) can collectively be considered as a switchable terminating resistor of the node n. Indeed, as shown, the electrical resistor <NUM>(n) and the electrical switch <NUM>(n) can form a series connection that couples the high-line <NUM> to the low-line <NUM>, which series connection is in parallel with the node n. In various aspects, if the electrical switch <NUM>(n) is open, electric current from the high-line <NUM> and/or the low-line <NUM> can be unable to flow across the electrical resistor <NUM>(n). In such case, the switchable terminating resistor collectively formed by the electrical resistor <NUM>(n) and the electrical switch <NUM>(n) can be considered as electrically inactive, and the node n can thus be considered to be in a non-terminating state. That is, if the electrical switch <NUM>(n) is open, the electrical resistor <NUM>(n) can fail to apply a terminating resistance to (e.g., in parallel with) the node n. On the other hand, if the electrical switch <NUM>(n) is closed, electric current from the high-line <NUM> and/or the low-line <NUM> can flow across the electrical resistor <NUM>(n). In such case, the switchable terminating resistor collectively formed by the electrical resistor <NUM>(n) and the electrical switch <NUM>(n) can be considered as electrically active, and the node n can thus be considered to be in a terminating state. That is, if the electrical switch <NUM>(n) is closed, the electrical resistor <NUM>(n) can apply a terminating resistance to (e.g., in parallel with) the node n.

Those having ordinary skill in the art will appreciate that the characteristics and/or properties of such switchable terminating resistors can be configured and/or set in any suitable way as desired. For instance, the resistance values of such switchable terminating resistors can be any suitable values as desired (e.g., the terminating resistance of one node can be equal to and/or different from the terminating resistance of any other node).

Furthermore, those having ordinary skill in the art will appreciate that a switchable terminating resistor can be constructed via any suitable number of electrical resistors and/or any suitable number of electrical switches that are configured and/or arranged in any suitable fashion and/or pattern. As an example, the electrical resistor <NUM>(<NUM>) is shown as a single resistor for ease of illustration; however, the electrical resistor <NUM>(<NUM>) can be an equivalent resistance formed by any suitable number of parallel and/or series resistors (and/or other circuit elements), as desired. Similarly, the electrical resistor <NUM>(j) is shown as a single resistor for ease of illustration; however, the electrical resistor <NUM>(j) can be an equivalent resistance formed by any suitable number of parallel and/or series resistors (and/or other circuit elements), as desired. Likewise, the electrical resistor <NUM>(n) is shown as a single resistor for ease of illustration; however, the electrical resistor <NUM>(n) can be an equivalent resistance formed by any suitable number of parallel and/or series resistors (and/or other circuit elements), as desired.

In any case, each of the set of nodes <NUM> can be in parallel with a corresponding switchable terminating resistor, such that each node can be converted from a non-terminating state to a terminating state, and/or vice versa, as desired. Because the node <NUM> and the node n can be at the physical endpoints of the CAN bus <NUM>, the node <NUM> and the node n can initially be placed in the terminating states, while the rest of the set of nodes <NUM> can initially be placed in the non-terminating states.

<FIG> illustrates a block diagram of an example system <NUM> including an impedance sensor and an impedance that can facilitate smart CAN termination in accordance with one or more embodiments described herein. As shown, the system <NUM> can, in some cases, comprise the same components as the system <NUM>, and can further comprise an impedance sensor <NUM> and/or an impedance <NUM>.

In various aspects, the sensor component <NUM> can comprise the impedance sensor <NUM>. In various aspects, the impedance sensor <NUM> can be any suitable device that can be electrically integrated with the CAN bus <NUM> so as to measure and/or otherwise quantify the impedance <NUM> of the CAN bus <NUM>. In various aspects, the impedance <NUM> can be a level of impedance exhibited by the CAN bus <NUM> (e.g., exhibited between the high-line <NUM> and/or the low-line <NUM>) at any given time. In various other aspects, the impedance <NUM> can be an average level of impedance exhibited by the CAN bus <NUM> over any given interval of time. In any case, the impedance <NUM> can be exhibited by the CAN bus <NUM>, and the impedance sensor <NUM> can, via any suitable digital and/or analog technique, measure and/or detect the impedance <NUM>. As a non-limiting example, the impedance sensor <NUM> can be any suitable impedance analyzer and/or multimeter. As another example, the impedance sensor <NUM> can be any suitable combination of circuitry (e.g., differential amplifiers, buffer amplifiers, division circuits, lowpass and/or high-pass filters, comparators) that can be configured to measure electrical impedance.

<FIG> illustrates a block diagram of an example, system <NUM> including a single-loss threshold and a double-loss threshold that can facilitate smart CAN termination in accordance with one or more embodiments described herein. As shown, the system <NUM> can, in some cases, comprise the same components as the system <NUM>, and can further comprise a single-loss threshold <NUM> and/or a double-loss threshold <NUM>.

In various embodiments, the comparison component <NUM> can have any suitable form of electronic access to the single-loss threshold <NUM> and/or to the double-loss threshold <NUM>. In various aspects, the single-loss threshold <NUM> can be any suitable impedance value that represents a minimum level of impedance that can be exhibited and/or that can be expected to be exhibited by the CAN bus <NUM> when only one of the terminating nodes of the CAN bus <NUM> is lost. Those having ordinary skill in the art will understand that the magnitude of the single-loss threshold <NUM> can depend upon the electrical properties and/or characteristics of the CAN bus <NUM> (e.g., can depend upon the terminating resistances implemented in the CAN bus <NUM>, can depend upon the number of nodes in the set of nodes <NUM>, can depend upon any other circuitry and/or loads that are involved with the CAN bus <NUM>). Accordingly, those having ordinary skill in the art will appreciate that, in various cases, the single-loss threshold <NUM> can be determined experimentally and/or analytically based on the CAN bus <NUM>.

Similarly, in various aspects, the double-loss threshold <NUM> can be any suitable impedance value that represents a minimum level of impedance that can be exhibited and/or that can be expected to be exhibited by the CAN bus <NUM> when both of the terminating nodes of the CAN bus <NUM> are lost. Those having ordinary skill in the art will understand that the magnitude of the double-loss threshold <NUM> can depend upon the electrical properties and/or characteristics of the CAN bus <NUM> (e.g., can depend upon the terminating resistances implemented in the CAN bus <NUM>, can depend upon the number of nodes in the set of nodes <NUM>, can depend upon any other circuitry and/or loads that are involved with the CAN bus <NUM>). Accordingly, those having ordinary skill in the art will appreciate that, in various cases, the double-loss threshold <NUM> can be determined experimentally and/or analytically based on the CAN bus <NUM>.

In various instances, the double-loss threshold <NUM> can be larger than the single-loss threshold <NUM>, due to the rule governing how resistances in parallel sum together.

In various aspects, the comparison component <NUM> can compare the impedance <NUM> to the single-loss threshold <NUM> and/or to the double-loss threshold <NUM>, so as to conclude and/or determine whether and/or how many of the terminating nodes of the CAN bus <NUM> are lost. More specifically, in various instances, the comparison component <NUM> can compare the impedance <NUM> to the double-loss threshold <NUM>. If the comparison component <NUM> determines that the impedance <NUM> is greater than the double-loss threshold <NUM>, the comparison component <NUM> can conclude that the CAN bus <NUM> has lost both of its terminating nodes. On the other hand, if the comparison component <NUM> determines, that the impedance <NUM> is not greater than the double-loss threshold <NUM>, the comparison component <NUM> can compare the impedance <NUM> to the single-loss threshold <NUM>. If the comparison component <NUM> determines that the impedance <NUM> is greater than the single-loss threshold <NUM>, the comparison component <NUM> can conclude that the CAN bus <NUM> has lost only one of its terminating nodes. On the other hand, if the comparison component <NUM> determines that the impedance <NUM> is not greater than the single-loss threshold <NUM>, the comparison component <NUM> can conclude that the CAN bus <NUM> has not lost any of its terminating nodes.

In other words, the following determinations can be made by the comparison component <NUM> in various cases. If the impedance <NUM> is less than both the single-loss threshold <NUM> and the double-loss threshold <NUM>, it can be inferred that neither terminating node is lost. If the impedance <NUM> is greater than the single-loss threshold <NUM> but lesser than the double-loss threshold <NUM>, it can be inferred that one of the terminating nodes is lost. If the impedance <NUM> is greater than both the single-loss threshold <NUM> and the double-loss threshold <NUM>, it can be inferred that both of the terminating nodes are lost.

<FIG> illustrates a block diagram of an example, system <NUM> including terminating activation signals that can facilitate smart CAN termination in accordance with one or more embodiments described herein. As shown, the system <NUM> can, in some cases, comprise the same components as the system <NUM>, and can further comprise a set of termination control signals <NUM>.

In various embodiments, the termination component <NUM> can electronically transmit the set of termination control signals <NUM> to one or more nodes in the set of nodes <NUM>, based on the conclusion/determination of the comparison component <NUM>.

For example, suppose that the comparison component <NUM> concludes that both terminating nodes of the CAN bus <NUM> are lost. That is, node <NUM> and node n can be lost. In such case, the termination component <NUM> can identify two remaining nodes of the set of nodes <NUM> that are respectively adjacent to the two lost terminating nodes. Here, node <NUM> can be a lost terminating node, and node <NUM> (not shown) can be a remaining node that is adjacent to node <NUM>. Similarly, node n can be a lost terminating node, and node n - <NUM> (not shown) can be a remaining node that is adjacent to node n. Accordingly, the termination component <NUM> can convert the node <NUM> and the node n — <NUM> from non-terminating states to terminating states. That is, the switchable terminating resistor of node <NUM> can be electrically inactive, and the termination component <NUM> can transmit a first termination control signal to the switchable terminating resistor of node <NUM>, thereby causing the switchable terminating resistor of node <NUM> to become electrically active. Likewise, the switchable terminating resistor of node n - <NUM> can be electrically inactive, and the termination component <NUM> can transmit a second termination control signal to the switchable terminating resistor of node n - <NUM>, thereby causing the switchable terminating resistor of node n — <NUM> to become electrically active. In such case, the first and second termination control signals can be considered as the set of termination control signals <NUM>.

Thus, in this example, node <NUM> and node n were the initial two terminating nodes of the CAN bus <NUM>, the CAN bus <NUM> lost connection with both node <NUM> and node n, and the termination component <NUM> converted node <NUM> and node n - <NUM> to termination states. In other words, node <NUM> can be considered as a new terminating node that functionally replaces the lost terminating node <NUM>, and node n — <NUM> can be considered as a new terminating node that functionally replaces the lost terminating node n.

As another example, suppose that the comparison component <NUM> concludes that only one terminating node of the CAN bus <NUM> is lost. For purposes of this example, suppose that node n is lost while node <NUM> is not lost. In such case, the termination component <NUM> can identify which of the two terminating nodes is lost. For instance, the termination component <NUM> can attempt to communicate with both terminating nodes, and the termination component <NUM> can determine that whichever terminating node fails to properly respond to such attempted communication is lost. Here, the termination component <NUM> can request a particular type of response from both node <NUM> and node n. Since node <NUM> is not lost, node <NUM> can properly respond to the request. However, since node n is lost, node n can fail to properly respond to the request. Due to the failure of node n to properly respond, the termination component <NUM> can determine that the node n is lost. Once the lost terminating node is identified, the termination component <NUM> can identify one remaining node of the set of nodes <NUM> that is adjacent to the lost terminating node. Here, node n can be the lost terminating node, and node n -- <NUM> (not shown) can be a remaining node that is adjacent to node n. Accordingly, the termination component <NUM> can convert the node n — <NUM> from a non-terminating state to a terminating state. That is, the switchable terminating resistor of node n - <NUM> can be electrically inactive, and the termination component <NUM> can transmit a termination control signal to the switchable terminating resistor of node n - <NUM>, thereby causing the switchable terminating resistor of node n — <NUM> to become electrically active. In such case, this termination control signal can be considered as the set of termination control signals <NUM> (e.g., a set can contain one or more).

Thus, in this example, node <NUM> and node n were the initial two terminating nodes of the CAN bus <NUM>, the CAN bus <NUM> lost connection with node n, and the termination component <NUM> converted node n — <NUM> to a termination state. In other words, node n - <NUM> can be considered as a new terminating node that functionally replaces the lost terminating node n. Thus, the termination nodes of the CAN bus <NUM> in this example can now be node <NUM> and node n — <NUM>.

As yet another example, suppose that the comparison component <NUM> concludes that only one terminating node of the CAN bus <NUM> is lost, and suppose that node <NUM> is lost while node n is not lost. In such case, the termination component <NUM> can identify which of the two terminating nodes is lost. Again, this can be facilitated by attempting to communicate with both terminating nodes and identifying as lost whichever terminating node fails to properly respond to such attempted communication. Here, the termination component <NUM> can request a particular type of response from both node <NUM> and node n. Since node n is not lost, node n can properly respond to the request. However, since node <NUM> is lost, node <NUM> can fail to properly respond to the request. Due to the failure of node <NUM> to properly respond, the termination component <NUM> can determine that the node <NUM> is lost. Once the lost terminating node is identified, the termination component <NUM> can identify one remaining node of the set of nodes <NUM> that is adjacent to the lost terminating node. Here, node <NUM> can be the lost terminating node, and node <NUM> (not shown) can be a remaining node that is adjacent to node <NUM>. Accordingly, the termination component <NUM> can convert the node <NUM> from a non-terminating state to a terminating state. That is, the switchable terminating resistor of node <NUM> can be electrically inactive, and the termination component <NUM> can transmit a termination control signal to the switchable terminating resistor of node <NUM>, thereby causing the switchable terminating resistor of node <NUM> to become electrically active. In such case, this termination control signal can be considered as the set of termination control signals <NUM> (e.g., a set can contain one or more).

Thus, in this example, node <NUM> and node n were the initial two terminating nodes of the CAN bus <NUM>, the CAN bus <NUM> lost connection with node <NUM>, and the termination component <NUM> converted node <NUM> to a termination state. In other words, node <NUM> can be considered as a new terminating node that functionally replaces the lost terminating node <NUM>. Thus, the termination nodes of the CAN bus <NUM> in this example can now be node <NUM> and node n.

In various embodiments, the sensor component <NUM>, the comparison component <NUM>, and/or the termination component <NUM> can repeat their above-described functionalities at any suitable intervals (e.g., the sensor component <NUM> can periodically measure the impedance of the CAN bus <NUM>; whenever the sensor component <NUM> measures an impedance, the comparison component <NUM> can determine whether and/or how many terminating nodes are lost based on the impedance; whenever the comparison component <NUM> generates a determination as to whether and/or how many terminating nodes are lost, the termination component can convert non-terminating nodes to terminating nodes as appropriate).

<FIG> illustrates a flow diagram of an example, computer-implemented method <NUM> that can facilitate smart CAN termination in accordance with one or more embodiments described herein. In various cases, the computer-implemented method <NUM> can be facilitated by the smart CAN bus termination system <NUM>.

In various embodiments, act <NUM> can comprise measuring, by a device (e.g., <NUM>) operatively coupled to a processor, an impedance (e.g., <NUM>) across a CAN bus having two terminating nodes (e.g., node <NUM> and node n).

In various aspects, act <NUM> can include determining, by the device (e.g., <NUM>), whether the measured impedance exceeds a double-loss threshold (e.g., <NUM>). In other words, the device can determine whether both terminating nodes of the CAN bus are lost. If yes, the computer-implemented method <NUM> can proceed to act <NUM>. If not, the computer-implemented method <NUM> can proceed to act <NUM>.

In various instances, act <NUM> can include identifying, by the device (e.g., <NUM>), two non-terminating nodes (e.g., node <NUM> and node n - <NUM>) that are respectively adjacent to the two lost terminating nodes.

In various cases, act <NUM> can include transmitting, by the device (e.g., <NUM>), activation signals (e.g., <NUM>), to the two non-terminating nodes, thereby converting them into terminating nodes. In various aspects, the computer-implemented method <NUM> can proceed back to act <NUM>.

In various instances, act <NUM> can include determining, by the device (e.g., <NUM>), whether the measured impedance exceeds a single-loss threshold (e.g., <NUM>). In other words, the device can determine whether only one of the terminating nodes of the CAN bus is lost. If yes, the computer-implemented method <NUM> can proceed to act <NUM>. If not, the computer-implemented method <NUM> can proceed back to act <NUM>.

In various cases, act <NUM> can include identifying, by the device (e.g., <NUM>), a non-terminating node that is adjacent to the lost terminating node (e.g., if node <NUM> is lost, node <NUM> can be identified; if node n is lost, node n - <NUM> can be identified).

In various aspects, act <NUM> can include transmitting, by the device (e.g., <NUM>), a termination activation signal (e.g., <NUM>) to the non-terminating node, thereby converting it into a terminating node. In various cases, the computer-implemented method <NUM> can proceed back to act <NUM>.

As mentioned above, each node of the set of nodes <NUM> can correspond to a switchable terminating resistor. Those having ordinary skill in the art will appreciate that a switchable terminating resistor can comprise any suitable number of electrical resistance elements arranged in any suitable fashions (e.g., such electrical resistance elements can be arranged in parallel and/or in series with each other). Moreover, those having ordinary skill in the art will appreciate that the switchable terminating resistor can also comprise any suitable number of electrical switches that are coupled in any suitable arrangements to such any suitable electrical resistance elements. An example is shown with respect to <FIG>.

<FIG> illustrates a block diagram of an example, circuit architecture <NUM> that can facilitate smart CAN termination in accordance with one or more embodiments described herein. That is, <FIG> depicts an example embodiment of a switchable terminating resistor.

In various cases, there can be a node <NUM> from the set of nodes <NUM>. As shown, the node <NUM> can be coupled to both the high-line <NUM> and the low-line <NUM> of the CAN bus <NUM>.

In various aspects, any suitable circuitry can be implemented between the high-line <NUM> and the low-line <NUM> and in parallel with the node <NUM>, so as to achieve any suitable level of energy absorption and/or reflection along the CAN bus <NUM> with respect to the node <NUM>. According to the present invention, an electric choke <NUM> is applied to the high-line <NUM> and the low-line <NUM> in parallel with the node <NUM>. Moreover, in various aspects, a pair of capacitors <NUM>-<NUM> can be coupled between the high-line <NUM> and the low-line <NUM> on one side of the choke <NUM> (e.g., on the side of the choke <NUM> that is closer to the node <NUM>). In various cases, an interface between the pair of capacitors <NUM>-<NUM> can be grounded, as shown. Furthermore, in various instances, a pair of resistors <NUM>-<NUM> can be coupled between the high-line <NUM> and the low-line <NUM> on another side of the choke <NUM> (e.g., on the side of the choke <NUM> that is farther from the node <NUM>). As shown, an interface between the pair of resistors <NUM>-<NUM> can be wired to a capacitor <NUM> and then to ground. In various aspects, such circuitry can help to ensure that a desired level of energy absorption and/or energy reflection occurs at the node <NUM> on the CAN bus <NUM>. As those having ordinary skill in the art will understand, the properties and/or characteristics of such circuitry can be configured in any suitable way as desired. As some non-limiting examples, the choke <NUM> can exhibit an inductance of <NUM> micro Henrys, the capacitors <NUM>-<NUM> can each exhibit a capacitance of <NUM> pico Farads, the resistors <NUM>-<NUM> can each exhibit resistances of <NUM> kilo Ohms, and/or the capacitor <NUM> can exhibit a capacitance of <NUM> nano Farads.

According to the present invention, a switchable terminating resistor of the node <NUM> comprises a resistor <NUM>, a resistor <NUM>, an electrical switch <NUM>, an electrical switch <NUM>, a capacitor <NUM>, a resistor <NUM>, a resistor <NUM>, an electrical switch <NUM>, an electrical switch <NUM>, and a capacitor <NUM>. Indeed, a first portion of the switchable terminating resistor of the node <NUM> can comprise the resistor <NUM>, the resistor <NUM>, the electrical switch <NUM>, the electrical switch <NUM>, and the capacitor <NUM>. Moreover, a second portion of the switchable terminating resistor of the node <NUM> can comprise the resistor <NUM>, the resistor <NUM>, the electrical switch <NUM>, the electrical switch <NUM>, and the capacitor <NUM>.

Consider the first portion. As shown, the low-line <NUM> can be coupled to the electrical switch <NUM>, which can be coupled to the resistor <NUM>, which can be coupled to the resistor <NUM>, which can be coupled to the electrical switch <NUM>, which can be coupled to the high-line <NUM>. Moreover, as shown, the interface between the resistor <NUM> and the resistor <NUM> can be coupled to the capacitor <NUM>, which can then be coupled to ground. Furthermore, as shown, this first portion of the switchable terminating resistor of the node <NUM> can be located on the side of the choke <NUM> that is closest to the node <NUM>. As those having ordinary skill in the art will appreciate, the resistor <NUM>, the resistor <NUM>, and/or the capacitor <NUM> can have any suitable characteristics and/or properties as desired. As an example, the resistor <NUM> and the resistor <NUM> can each exhibit a resistance of <NUM> Ohms, and/or the capacitor <NUM> can exhibit a capacitance of <NUM> nano Farads.

Now, consider the second portion. As shown, the low-line <NUM> can be coupled to the electrical switch <NUM>, which can be coupled to the resistor <NUM>, which can be coupled to the resistor <NUM>, which can be coupled to the electrical switch <NUM>, which can be coupled to the high-line <NUM>. Additionally, as shown, the interface between the resistor <NUM> and the resistor <NUM> can be coupled to the capacitor <NUM>, which can then be coupled to ground. As shown, this second portion of the switchable terminating resistor of the node <NUM> can be located on the side of the choke <NUM> that is farthest from the node <NUM>. As those having ordinary skill in the art will appreciate, the resistor <NUM>, the resistor <NUM>, and/or the capacitor <NUM> can have any suitable characteristics and/or properties as desired. As a non-limiting example, the resistor <NUM> and the resistor <NUM> can each exhibit a resistance of <NUM> Ohms, and/or the capacitor <NUM> can exhibit a capacitance of <NUM> nano Farads.

As those having ordinary skill in the art will appreciate, the switchable terminating resistor of the node <NUM> can be considered as electrically inactive when the electrical switches <NUM>, <NUM>, <NUM>, and <NUM> are all open. In such case, the node <NUM> can be considered as being in a non-terminating state. On the other hand, the switchable terminating resistor of the node <NUM> can be considered as electrically active when the electrical switches <NUM>, <NUM>, <NUM>, and <NUM> are all closed. In such case, the node <NUM> can be considered as being in a terminating state. Thus, the node <NUM> can be converted from a non-terminating state to a terminating state (and/or vice versa) by closing (and/or opening) the electrical switches <NUM>, <NUM>, <NUM>, and <NUM>. Although not explicitly shown in <FIG>, those having ordinary skill in the art will appreciate that the termination component <NUM> can be coupled to the electrical switches <NUM>, <NUM>, <NUM>, and <NUM> via any suitable control-logic-circuitry and/or control-logic-wiring. In other words, the termination component <NUM> can transmit the set of termination control signals <NUM> to the electrical switches <NUM>, <NUM>, <NUM>, and <NUM> via such control-logic circuitry and/or wiring, such that the termination component <NUM> can controllably open and/or close the electrical switches <NUM>, <NUM>, <NUM>, and <NUM>.

<FIG> illustrates a flow diagram of an example computer-implemented method <NUM> that an facilitate smart CAN termination in accordance with one or more embodiments described herein. In various cases, the smart CAN bus termination system <NUM> can facilitate the computer-implemented method <NUM>.

In various embodiments, act <NUM> can include measuring, by a device (e.g., <NUM>) operatively coupled to a processor, an impedance (e.g., <NUM>) of a controller area network (CAN) bus (e.g., <NUM>).

In various aspects, act <NUM> can include converting, by the device (e.g., <NUM>), at least one node (e.g., one of <NUM>) from a non-terminating state to a terminating state, based on the impedance.

Although not explicitly shown in <FIG>, the at least one node of the CAN bus can be associated with a switchable terminating resistor (e.g., collectively <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>) having one or more switches (e.g., <NUM>, <NUM>, <NUM>, and <NUM>), wherein the at least one node is in the non-terminating state when the one or more switches are open, and wherein the at least one node is in the terminating state when the one or more switches are closed.

Although not explicitly shown in <FIG>, according to the present invention, the converting the at least one node from the non-terminating state to the terminating state comprises: transmitting, by the device (e.g., <NUM>), a control signal (e.g., <NUM>) to the one or more switches, which can cause the one or more switches to close.

Although not explicitly shown in <FIG>, the CAN bus can include a high-line (e.g., <NUM>) and a low-line (e.g., <NUM>), and the switchable terminating resistor can include: a choke (e.g., <NUM>) applied to the high-line and the low-line; a first pair of resistors (e.g., <NUM> and <NUM>) in series with a first pair of switches (e.g., <NUM> and <NUM>) on a first side of the choke, wherein the first pair of resistors in series with the first pair of switches couple the high-line to the low-line when the first pair of switches are closed; and a second pair of resistors (e.g., <NUM> and <NUM>) in series with a second pair of switches (e.g., <NUM> and <NUM>) on a second side of the choke, wherein the second pair of resistors in series with the second pair of switches couple the high-line to the low-line when the second pair of switches are closed.

Although not explicitly shown in <FIG>, the computer-implemented method <NUM> can further comprise: comparing, by the device (e.g., <NUM>), the impedance to a first threshold value (e.g., <NUM>), wherein the converting the at least one node comprises converting, by the device (e.g., <NUM>), one of the at least one node from the non-terminating state to the terminating state based on the comparing indicating that the impedance exceeds the first threshold value.

Although not explicitly shown in <FIG>, the computer-implemented method <NUM> can further comprise: comparing, by the device (e.g., <NUM>), the impedance to a second threshold value (e.g., <NUM>) that is higher than the first threshold value, wherein the converting the at least one node comprises converting, by the device (e.g., <NUM>), two of the at least one node from non-terminating states to terminating states based on the comparing indicating that the impedance exceeds the second threshold value.

Although not explicitly shown in <FIG>, the CAN bus can be a controller area network flexible data-rate (CAN-FD) bus.

Various embodiments of the invention constitute a computerized tool that can electronically monitor the impedance of a CAN bus; that can electronically determine whether and/or how many terminating nodes of the CAN bus are lost, based on the impedance; and/or that can electronically convert one or more remaining nodes of the CAN bus from non-terminating states to terminating states, so as to replace the lost terminating nodes. Accordingly, an amount of time during which the CAN bus is not properly terminated and is thus experiencing degraded performance can be decreased by the computerized tool. Indeed, experimental simulations conducted by the inventors of various embodiments of the invention verified that the computerized tool described herein can restore signal quality and/or electromagnetic compatibility of a CAN bus when one or more terminating nodes of the CAN bus are lost. Thus, the computerized tool as described herein can be considered as a concrete and tangible technical improvement in the field of controller area networks.

In order to provide additional context for various embodiments described herein, <FIG> and the following discussion are intended to provide a brief, general description of a suitable computing environment <NUM> in which the various embodiments of the embodiment described herein can be implemented. While the embodiments have been described above in the general context of computer-executable instructions that can run on one or more computers, those skilled in the art will recognize that the embodiments can be also implemented in combination with other program modules and/or as a combination of hardware and software.

Generally, program modules include routines, programs, components, data structures, etc., that perform particular tasks or implement particular abstract data types.

The illustrated embodiments of the embodiments herein can be also practiced in distributed computing environments where certain tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules can be located in both local and remote memory storage devices.

Computer-readable storage media can include, but are not limited to, random access memory (RAM), read only memory (ROM), electrically erasable programmable read only memory (EEPROM), flash memory or other memory technology, compact disk read only memory (CD ROM), digital versatile disk (DVD), Blu-ray disc (BD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, solid state drives or other solid state storage devices, or other tangible and/or non-transitory media which can be used to store desired information.

Computer-readable storage media can be accessed by one or more local or remote computing devices, e.g., via access requests, queries or other data retrieval protocols, for a variety of operations with respect to the information stored by the medium.

Communications media typically embody computer-readable instructions, data structures, program modules or other structured or unstructured data in a data signal such as a modulated data signal, e.g., a carrier wave or other transport mechanism, and includes any information delivery or transport media. The term "modulated data signal" or signals refers to a signal that has one or more of its characteristics set or changed in such a manner as to encode information in one or more signals. By way of example, communication media include wired media, such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media.

With reference again to <FIG>, the example environment <NUM> for implementing various embodiments of the aspects described herein includes a computer <NUM>, the computer <NUM> including a processing unit <NUM>, a system memory <NUM> and a system bus <NUM>. The system bus <NUM> couples system components including, but not limited to, the system memory <NUM> to the processing unit <NUM>. The processing unit <NUM> can be any of various commercially available processors. Dual microprocessors and other multi processor architectures can also be employed as the processing unit <NUM>.

The system bus <NUM> can be any of several types of bus structure that can further interconnect to a memory bus (with or without a memory controller), a peripheral bus, and a local bus using any of a variety of commercially available bus architectures. The system memory <NUM> includes ROM <NUM> and RAM <NUM>. A basic input/output system (BIOS) can be stored in a non-volatile memory such as ROM, erasable programmable read only memory (EPROM), EEPROM, which BIOS contains the basic routines that help to transfer information between elements within the computer <NUM>, such as during startup. The RAM <NUM> can also include a highspeed RAM such as static RAM for caching data.

The computer <NUM> further includes an internal hard disk drive (HDD) <NUM> (e.g., EIDE, SATA), one or more external storage devices <NUM> (e.g., a magnetic floppy disk drive (FDD) <NUM>, a memory stick or flash drive reader, a memory card reader, etc.) and a drive <NUM>, e.g., such as a solid state drive, an optical disk drive, which can read or write from a disk <NUM>, such as a CD-ROM disc, a DVD, a BD, etc. Alternatively, where a solid state drive is involved, disk <NUM> would not be included, unless separate. While the internal HDD <NUM> is illustrated as located within the computer <NUM>, the internal HDD <NUM> can also be configured for external use in a suitable chassis (not shown). Additionally, while not shown in environment <NUM>, a solid state drive (SSD) could be used in addition to, or in place of, an HDD <NUM>. The HDD <NUM>, external storage device(s) <NUM> and drive <NUM> can be connected to the system bus <NUM> by an HDD interface <NUM>, an external storage interface <NUM> and a drive interface <NUM>, respectively. The interface <NUM> for external drive implementations can include at least one or both of Universal Serial Bus (USB) and Institute of Electrical and Electronics Engineers (IEEE) <NUM> interface technologies. Other external drive connection technologies are within contemplation of the embodiments described herein.

The drives and their associated computer-readable storage media provide nonvolatile storage of data, data structures, computer-executable instructions, and so forth. For the computer <NUM>, the drives and storage media accommodate the storage of any data in a suitable digital format.

A number of program modules can be stored in the drives and RAM <NUM>, including an operating system <NUM>, one or more application programs <NUM>, other program modules <NUM> and program data <NUM>. All or portions of the operating system, applications, modules, and/or data can also be cached in the RAM <NUM>.

The computer <NUM> can operate in a networked environment using logical connections via wired and/or wireless communications to one or more remote computers, such as a remote computer(s) <NUM>. The remote computer(s) <NUM> can be a workstation, a server computer, a router, a personal computer, portable computer, microprocessor-based entertainment appliance, a peer device or other common network node, and typically includes many or all of the elements described relative to the computer <NUM>, although, for purposes of brevity, only a memory/storage device <NUM> is illustrated. The logical connections depicted include wired/wireless connectivity to a local area network (LAN) <NUM> and/or larger networks, e.g., a wide area network (WAN) <NUM>.

When used in a LAN networking environment, the computer <NUM> can be connected to the local network <NUM> through a wired and/or wireless communication network interface or adapter <NUM>. The adapter <NUM> can facilitate wired or wireless communication to the LAN <NUM>, which can also include a wireless access point (AP) disposed thereon for communicating with the adapter <NUM> in a wireless mode.

When used in a WAN networking environment, the computer <NUM> can include a modem <NUM> or can be connected to a communications server on the WAN <NUM> via other means for establishing communications over the WAN <NUM>, such as by way of the Internet. The modem <NUM>, which can be internal or external and a wired or wireless device, can be connected to the system bus <NUM> via the input device interface <NUM>. In a networked environment, program modules depicted relative to the computer <NUM> or portions thereof, can be stored in the remote memory/storage device <NUM>.

When used in either a LAN or WAN networking environment, the computer <NUM> can access cloud storage systems or other network-based storage systems in addition to, or in place of, external storage devices <NUM> as described above, such as but not limited to a network virtual machine providing one or more aspects of storage or processing of information. Generally, a connection between the computer <NUM> and a cloud storage system can be established over a LAN <NUM> or WAN <NUM> e.g., by the adapter <NUM> or modem <NUM>, respectively. Upon connecting the computer <NUM> to an associated cloud storage system, the external storage interface <NUM> can, with the aid of the adapter <NUM> and/or modem <NUM>, manage storage provided by the cloud storage system as it would other types of external storage. For instance, the external storage interface <NUM> can be configured to provide access to cloud storage sources as if those sources were physically connected to the computer <NUM>.

As shown, cloud computing environment <NUM> includes one or more cloud computing nodes <NUM> with which local computing devices used by cloud consumers, such as, for example, personal digital assistant (PDA) or cellular telephone <NUM>, desktop computer <NUM>, laptop computer <NUM>, and/or automobile computer system <NUM> may communicate. It is understood that the types of computing devices <NUM>-<NUM> shown in <FIG> are intended to be illustrative only and that computing nodes <NUM> and cloud computing environment <NUM> can communicate with any type of computerized device over any type of network and/or network addressable connection (e.g., using a web browser).

Repetitive description of like elements employed in other embodiments described herein is omitted for sake of brevity. It should be understood in advance that the components, layers, and functions shown in <FIG> are intended to be illustrative only. As depicted, the following layers and corresponding functions are provided.

Workloads layer <NUM> provides examples of functionality for which the cloud computing environment may be utilized. Examples of workloads and functions which may be provided from this layer include: mapping and navigation <NUM>; software development and lifecycle management <NUM>; virtual classroom education delivery <NUM>; data analytics processing <NUM>; transaction processing <NUM>; and differentially private federated learning processing <NUM>. Various embodiments of the present invention can utilize the cloud computing environment described with reference to <FIG> and <FIG> to execute one or more differentially private federated learning process in accordance with various embodiments described herein.

The computer program product can include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present invention. The computer readable storage medium can be, for example, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium can also include the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing.

A network adaptor card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device.

These computer readable program instructions can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions can also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks. The computer readable program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational acts to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks.

The flowcharts and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention.

Moreover, those skilled in the art will appreciate that the inventive computer-implemented methods can be practiced with other computer system configurations, including single-processor or multiprocessor computer systems, mini-computing devices, mainframe computers, as well as computers, hand-held computing devices (e.g., PDA, phone), microprocessor-based or programmable consumer or industrial electronics, and the like. The illustrated aspects can also be practiced in distributed computing environments in which tasks are performed by remote processing devices that are linked through a communications network. However, some, if not all aspects of this disclosure can be practiced on stand-alone computers. In a distributed computing environment, program modules can be located in both local and remote memory storage devices.

Claim 1:
A system (<NUM>) for facilitating smart CAN termination, comprising a smart CAN bus termination system (<NUM>) electronically integrated with a CAN bus (<NUM>),
wherein said smart CAN bus termination system (<NUM>) comprises :
a processor (<NUM>) that executes computer-executable components stored in a computer-readable memory (<NUM>), the computer-executable components comprising:
a sensor component (<NUM>) that measures an impedance of a controller area network, CAN bus (<NUM>); and
a termination component (<NUM>) that converts at least one node of the CAN bus (<NUM>) from a non-terminating state to a terminating state, based on the impedance,
wherein the at least one node of the CAN bus (<NUM>) is associated with a switchable terminating resistor having one or more switches (<NUM>), wherein the at least one node is in the non-terminating state when the one or more switches (<NUM>) are open, and wherein the at least one node is in the terminating state when the one or more switches (<NUM>) are closed,
wherein the termination component (<NUM>) converts the at least one node from the non-terminating state to the terminating state by transmitting a control signal (<NUM>) to the one or more switches, which causes the one or more switches (<NUM>) to close, and
wherein the CAN bus (<NUM>) includes a high-line (<NUM>) and a low-line (<NUM>), said system (<NUM>) being characterized in that the switchable terminating resistor includes
a choke (<NUM>) applied to the high-line (<NUM>) and the low-line (<NUM>);
a first pair of resistors (<NUM>, <NUM>) in series with a first pair of switches (<NUM>, <NUM>) on a first side of the choke (<NUM>), wherein the first pair of resistors (<NUM>, <NUM>) in series with the first pair of switches (<NUM>, <NUM>) couple the high-line (<NUM>) to the low-line (<NUM>) when the first pair of switches (<NUM>, <NUM>) are closed; and
a second pair of resistors (<NUM>, <NUM>) in series with a second pair of switches (<NUM>, <NUM>) on a second side of the choke (<NUM>), wherein the second pair of resistors (<NUM>, <NUM>) in series with the second pair of switches (<NUM>, <NUM>) couple the high-line (<NUM>) to the low-line (<NUM>) when the second pair of switches (<NUM>, <NUM>) are closed.