CN-116601923-B - Method for fast refreshing of sensor nodes via an ethernet network

CN116601923BCN 116601923 BCN116601923 BCN 116601923BCN-116601923-B

Abstract

A method for fast refreshing of sensor nodes via an ethernet network having a head node and a plurality of associated nodes, wherein the method comprises a) determining a number of active nodes by the head node, b) classifying the identified nodes into two or more node classes to prioritize communication of the ethernet network by the head node, c) receiving reservation requests from at least some of the plurality of nodes by the head node, d) assigning time slots to one or more nodes in an upcoming communication window in response to reservation requests, wherein the assignments are based on node priorities and the priorities are assigned to the nodes according to the classes of the nodes, wherein after determining the number of active nodes, a necessary download data rate is determined and a current bus utilization is determined, wherein the bus utilization is determined by calculating a time difference of a final beacon and the number of nodes, and a bus cycle of the ethernet network is optimized in respect of the necessary download data rate.

Inventors

H. Ziner
D. HOPF

Assignees

大陆汽车科技有限公司

Dates

Publication Date: 20260505
Application Date: 20211130
Priority Date: 20201203

Claims (8)

1. A method for fast refreshing a sensor node via an ethernet network having a head node and a plurality of associated nodes, wherein the method comprises: a) Determining, by the head node, a number of active nodes; b) Classifying the identified nodes into two or more node categories, prioritizing communications of the ethernet network by the head node, C) A reservation request is received by the head node from at least some of the plurality of nodes, D) In response to the reservation request, time slots are assigned to one or more nodes in the upcoming communication window, wherein the assignments are based on node priorities assigned to the nodes according to their categories, Wherein after determining the number of active nodes, each node transmits only one frame in each transmission period and determines the time slots of the inactive nodes and makes use thereof for the head node, determining the necessary download data rate calculated in relation to the 10 Mbit ethernet bus and determining the current bus utilization by the head node, the head node determining which data has to be transmitted in which time unit, the absolute data rate on the bus being determined taking account of the overhead in the data transmission; Optimizing bus cycles of the ethernet network in terms of necessary download data rates, which is required to shorten the refresh time of the sensor nodes, wherein after the necessary download data rates are determined, a current idle data rate in the ethernet network in the last bus cycle of the ethernet network is determined (D frei ), and a necessary data rate for each bus cycle is determined (D zus ), wherein if the idle data rate in the ethernet network in the last bus cycle of the ethernet network (D frei ) is greater than or equal to the necessary data rate for each bus cycle (D zus ), no change is made in the next bus cycle, and if the idle data rate in the ethernet network in the last bus cycle of the ethernet network (D frei ) is less than the necessary data rate for each bus cycle, a change is made in the next bus cycle.
2. The method of claim 1 wherein the bus utilization is continuously monitored.
3. A control unit for an ethernet network, the control unit being designed as a first node, the first node being the control unit: -sending and receiving signals to and from a second control unit of the ethernet network; -determining the propagation time of the signal on the connection path to the second control unit; -determining a maximum speed of the connection path based on the propagation time; determining the type of transmission medium of the connection path based on the maximum speed, The control unit comprises at least: the microprocessor is provided with a microprocessor which is coupled to the microprocessor, A volatile memory and a non-volatile memory, At least two communication interfaces are provided for the purpose of, The timer can be synchronized with the time of the timer, The non-volatile memory contains program instructions which, when executed by the microprocessor, are capable of implementing and executing the method as claimed in claim 1 or 2.
4. An ethernet network for a motor vehicle, having a first control unit and a second control unit, wherein the control units are connected to one another by at least one connection path, the first control unit being configured according to claim 3.
5. An Ethernet network for a motor vehicle as recited in claim 4, wherein, The ethernet network comprises a third control unit (5) which is only indirectly connected to the first control unit (3) and which is directly connected to the second control unit via a third connection path, wherein the third control unit is designed to determine the propagation time of the third signal on the third connection path, wherein the first control unit is designed to trigger the determination of the propagation time of the third signal via a service message to the third control unit.
6. A computer program product comprising instructions which, when the program is executed by a computer, cause the computer to perform the method (200) as claimed in claim 1 or 2.
7. A computer readable medium having stored thereon the computer program product of claim 6.
8. A vehicle comprising an ethernet network having a plurality of control units according to claim 3.

Description

Method for fast refreshing of sensor nodes via an ethernet network Background With the advent of 10Mbit/s (IEEE 802.3 ch), in addition to 100Mbit/s, 1000Mbit/s and ongoing gigabit standardization, other Ethernet standards will be used for automotive applications. Ethernet and wireless technology now began to enter the car and its open and standardized protocols provided for the first time the possibility of attacking the car also from the outside. There are more and more reports on attacking vehicles in which an attacker tries to access the vehicle via radio waves, thereby also being able to access important functions of the vehicle. One variation of the new standard is a CSMA/CD based multipoint (MultiDrop) mode. This is very different from other ethernet variants (> 10 Mbit/s) because it is pursued to be able to design the ethernet more cost-effectively and thus also to solve simpler control devices. This standard does not require any switches (switch ICs) but is designed as a bus (similar to CAN). This approximately halves the number of PHYs (transceiver/port physical layers) required. Thus, ethernet is becoming a powerful competitor to CAN/CAN-FD and FlexRay because of the ability to greatly reduce system costs. In addition, typical automotive interfaces (such as SPI rather than xMII) can also be used for communication between the controller and the physical transceiver/port physical layer (PHY). Fig. 1 compares the basic features of switched ethernet with "bus ethernet" (multipoint) as defined in IEEE standard IEEE p802.3cg. The most important difference here is that the resources, i.e. bus accesses, are only available exclusively in the switched ethernet network, which means that every ethernet node (ECU) needs to transmit at every time without collision in the process. In the new ethernet bus implementation with the multi-drop mode a shared medium is used, that is to say that the bus access must be waited before this resource is available. MARK The IEEE p802.3cg standard uses, inter alia, a newly defined mechanism (plca—physical layer collision avoidance) to avoid collisions during bus accesses and to implement fair access. In this case, only one PHY (physical transceiver) can receive access to the bus at any time exactly. This makes it possible to avoid collisions. The access is based on the so-called round-robin (round-robin) method. Each ECU (node) on the bus has the opportunity to make a transmission within a defined period (or sequence). The so-called head node, which assumes the function of the network controller, determines the period in this case and transmits the repeated "beacons" on the bus. Thus, each node starts a timer based on its previously defined identity IDs (which determines the order as to when they are allowed to transmit), and after the timer expires and it is recognized that they are round to transmit, the nodes are allowed to transmit. Fig. 2 shows the basic sequence of communication over an ethernet bus. After transmitting the beacon, it takes the turn of node 0 and when this node completes its transmission, it allows the next node to transmit again (typically only a single ethernet frame can be transmitted in each time slot). Fig. 3 shows a physical representation of an ethernet bus with branch lines. EP 2 585 A1 describes a system and method for scheduling network communications in a managed network may include a network controller identifying a plurality of network nodes, the network controller classifying the identified network nodes into two or more node categories for prioritizing network communications at a node level, the network controller receiving reservation requests from at least some of the plurality of network nodes, wherein the reservation requests request one or more time slots in an upcoming communication window for their respective network nodes, and the network controller assigning time slots in the upcoming communication window to one or more network nodes in response to the reservation requests, wherein the assigning is based on the priorities of the network nodes, and wherein the priorities are assigned to the nodes according to the categories of the nodes. This patent application describes the network controller creating a periodic Medium Access Plan (MAP) in which access operations of the network nodes are defined in each period. The basis is the required quality of service, reservation requests from the corresponding nodes and their priority/sub-priority, from which the network controller creates the MAP. The network controller may also automatically send the MAP message without a reservation request. In US 2005 213 503a1, according to some described embodiments, a coordinating device performs a bandwidth allocation procedure based on information from previously unsatisfied bandwidth allocation requests, and responds to current bandwidth allocation requests. The current bandwidth allocation request specifies an amount of bandwidth currently requeste