JP-2026074647-A - Data transmission system

Abstract

[Challenge] The objective is to provide a data transmission system that significantly reduces the required wiring, thereby enabling system miniaturization and improving design flexibility. [Solution] A data transmission system that shares power supply and data transmission comprises a first device and a second device. The first device comprises voltage control means and current monitoring means. The second device comprises a variable current source and a control unit. The first device transmits changes in voltage values controlled by the voltage control means as data to the second device, and detects and receives changes in current values transmitted by the second device as data using the current monitoring means. The control unit of the second device transmits data to the first device based on changes in current values changed by the variable current source. [Selection Diagram] Figure 3

Inventors

• 渡瀬 悠斗

Assignees

• 本田技研工業株式会社

Dates

Publication Date

20260507

Application Date

20241021

Claims (5)

1. A data transmission system that shares power supply and data transmission, The system comprises a first device and a second device, The first device comprises a voltage control means and a current monitoring means, The second device comprises a variable current source and a control unit, The first device transmits the change in the voltage value controlled by the voltage control means as data to the second device. The control unit of the second device transmits data to the first device based on the change in the current value altered by the variable current source. The first device detects and receives as data the change in the current value transmitted by the second device using the current monitoring means. Data transmission system.
2. The transmission from the first device to the second device is such that, during the period allocated for 1-bit transmission, the bus transmitting the data does not constantly become low due to changes in voltage value. The transmission from the second device to the first device is performed during a period when the bus transmitting data is not at a low level due to the change in the voltage value. The data transmission system according to claim 1.
3. The voltage value controlled by the voltage control means is the negation of RTI (Return to Zero inverted). The signal resulting from the current value changed by the variable current source is NRZ (Non Return to Zero). A data transmission system according to claim 1 or claim 2.
4. The voltage control means transmits the change in voltage value as data to the second device, with a first voltage value lower by a first predetermined value than the power supply voltage as the first level, and a second voltage value higher by a second predetermined value than the ground level as the second level. The data transmission system according to claim 1.
5. The variable current source transmits the change in current value as data to the first device, with a first current value that is a third predetermined value lower than the maximum current value as the first level, and a second current value that is a fourth predetermined value higher than the zero level as the second level. A data transmission system according to claim 1 or claim 4.

Description

This invention relates to a data transmission system. To reduce the amount of wiring required for inter-device communication lines, a communication method has been devised that shares power supply lines and communication signal lines. This method eliminates the need for separate signal lines by superimposing the communication signal onto the power supply. However, existing communication methods that share power supply and communication signal lines lacked a method to achieve a simple, multi-drop (one-to-many communication) communication method suitable for the throughput exceeding several Mbps used in embedded applications. For example, methods such as GMSL and CoaXPress, which utilize several Gbps bandwidths for signal lines, are excessive for communication speeds of around several Mbps, resulting in complex and large circuits. Furthermore, many of these methods do not support multi-drop. 1-Wire, developed as a simpler, lower-speed communication method for embedded applications, supports multi-drop, but because it uses bus voltage for both transmission and reception, its maximum communication speed is 120 kbps, making it difficult to achieve throughput exceeding several Mbps. As a conventional technology aimed at reducing the wiring of inter-device communication lines, a technology has been proposed that assumes unidirectional communication from multiple devices to a host (transmission from the host is only at the start of communication). In this first conventional technology, the topology is daisy-chain type, and four levels of symbol codes are used for data transmission due to bus current fluctuations (see, for example, Patent Document 1). Special Publication No. 2022-541713 This figure shows an example of the appearance of the data transmission system in the embodiment when it is a robot.This figure shows an example configuration of the data transmission system in the embodiment when used with a robot.This figure shows an example configuration of functions related to data transmission and reception of a control device according to an embodiment, and an example configuration of functions related to data transmission and reception of a device.This figure shows an example of data transmission and reception according to the embodiment.This figure shows an example of a host-side configuration and a device-side configuration using conventional 1-Wire technology.This figure shows an example of the configuration of data transmission and reception in the control circuit in the first embodiment.This figure shows an example of data transmission and reception in the first embodiment, and the relationship between the bus state and data transmission.This figure shows an overview of the timing of data transmission and reception in the second embodiment.This figure shows examples of data patterns such as NRZ and RZI. Embodiments of the present invention will be described below with reference to the drawings. Note that in the drawings used in the following description, the scale of each component has been appropriately changed to ensure that each component is recognizable. In all the figures used to illustrate the embodiments, components with the same function are given the same reference numerals, and repeated explanations are omitted. Furthermore, "based on XX" as used in this application means "based on at least XX," and includes cases where it is based on another element in addition to XX. Also, "based on XX" is not limited to cases where XX is used directly, but also includes cases where it is based on something that has been calculated or processed. "XX" is any element (for example, any information). <Example of a data transmission system configuration> First, an example of the configuration of the data transmission system 1 will be described. Figure 1 shows an example of the appearance of the data transmission system in this embodiment when it is a robot. As shown in Figure 1, the data transmission system 1 includes, for example, a control device 2 (first device) and a device 3 (second device). The control device 2 is composed of, for example, a personal computer, or a CPU (Central Processing Unit) and memory unit. The control device 2 and device 3 are connected to each other via a bus 4, as described later. The control device 2 may be installed inside the robot or connected to the outside of the robot. Device 3 includes, for example, the arms and hands, legs, head, and waist of a robot. Figure 1 shows an example of device 3, which includes the arms and hands. The first device 310 is, for example, a mechanism corresponding to the elbow of the right arm. The second device 320 is, for example, a mechanism corresponding to the wrist of the right arm. The examples of the first device 310 and the second device 320 described above are merely examples and are not limited to them. For example, the first device 310 may be a mechanism corresponding to the elbow of the left arm, and the second device 320 may be a mechanism