Method for operating a system with a multiplicity of nodes and a base station according to TDMA and a system for this purpose

• US 7,450,538 B2
• Filed: 08/06/2003
• Issued: 11/11/2008
• Est. Priority Date: 08/17/2002
• Status: Expired due to Fees

• Current Assignee: ABB Research Ltd. (ABB Ltd.)
• Original Assignee: ABB Research Ltd. (ABB Ltd.)
• Inventors: Dzung, Dacfey, Endresen, Jan, Apneseth, Christoffer, Vefling, Harald
• Primary Examiner(s): D AGOSTA, STEPHEN M
• Application Number:
  US10/516,612
• Publication Number:
  US 20060165026A1
• Time in Patent Office: 1,924 Days
• Field of Search: 370/322, 455/41.2, 455/41.3, 455/456.1, 455/556.1, 455/90.1
• US Class Current: 370/322
• CPC Class Codes: G05B 19/414 Structure of the control system, e.g. common controller or multiprocessor systems, interface to servo, programmable interface controller
• CPC Class Codes: G05B 2219/31189 Time multiplex
• CPC Class Codes: G05B 2219/33192 Radio link, wireless
• CPC Class Codes: G05B 2219/33248 Time window for each controller or controlled function
• CPC Class Codes: H04B 7/26 at least one of which is mobile
• CPC Class Codes: H04B 7/2643 using time-division multiple access [TDMA] H04B7/2615, H04B7/2618 take precedence
• CPC Class Codes: H04J 4/00 Combined time-division and frequency-division multiplex systems H04J13/00 takes precedence ; data transmission H04L5/26; telemetry G08C15/00
• CPC Class Codes: H04W 16/02 Resource partitioning among network components, e.g. reuse partitioning

Abstract

A method is proposed for operating a system according to TDMA (Time Division Multiple Access) with a multiplicity of wireless sensors and/or actuators as nodes (S.1 . . . S.n) and a base station (BS), said system being installed in a machine or installation, such as industrial robots or an automated manufacturing or production unit, whereby cyclical TDMA data transmission blocks are transmitted and each TDMA data transmission block is composed of consecutive time slots. Each time slot is allocated to a specific node. The uplink signals (UL.1 . . . UL.n) can be transmitted from the different nodes (S.1 . . . S.n) to the base station (BS) simultaneously on two, three or more different frequencies (f1, f2, f3) whereas the. downlink signals (DL) are transmitted from the base station (BSA) to the different nodes (S.1 . . . S.n) on only one frequency, which differs from the uplink frequencies. The time slots and the different uplink frequencies of the different nodes are defined once and are thereafter retained.

Claims

1. A system with a multiplicity of wireless sensors and/or actuators as nodes (S.1 . . . S.n) and a base station (BS), which is installed in a machine or installation, such as industrial robots or an automated manufacturing or production unit,

a) wherein the sensors have a sensor head which detects a sensor environment and the actuators have an actuator unit and a control unit to detect an actuator environment,

b) wherein cyclical TDMA data transmission blocks are transmitted and each TDMA data transmission block is composed of consecutive time slots,

c) wherein each time slot is allocated to a specific node,

d) wherein the base station receives uplink signals that comprise sensor signals from the sensors and signals indicating the current status of actuators,

e) wherein the uplink signals (UL.1 . . . UL.n) can be transmitted from the different nodes (S.1 . . . S.n) to the base station (BS) simultaneously on at least two different frequencies (f1, f2, . . . f3),

f) wherein the downlink signals (DL) are transmitted from the base station (BS) to the different nodes (S.1 . . . S.n) on only one frequency, which differs from the uplink frequencies,

g) wherein the downlink signals comprise control signals to activate/deactivate the actuators and signals to set specific parameters of the actuators sensors,

h) wherein the time slots and the different uplink frequencies of the different nodes are defined once and are thereafter retained, so that the receiver of the base station (BS) can identify the relevant sensor/actuator node (S.1 . . . S.n) from the number and frequency allocated to each time slot.

2. A method for operating a system according to TDMA (Time Division Multiple Access) with a fixed quantity n of wireless sensors and/or actuators as nodes (S.1 . . . S.n) and a base station (BS), wherein n is any positive integer, said system being installed in a machine or installation, such as industrial robots or an automated manufacturing or production unit,

a) wherein the sensors have a sensor head which detects the sensor environment and the actuators have an actuator unit and a control unit to detect the sensor environment,

b) wherein cyclical TDMA data transmission blocks are transmitted and each TDMA data transmission block is composed of consecutive time slots,

c) wherein each time slot is allocated to a specific node,

d) wherein the base station receives uplink signals that comprise sensor signals from the sensors and signals indicating the current status of actuators,

3. The method according to claim 2, wherein the different uplink frequencies of the different sensors and/or actuators (S.1 . . . S.n) and the downlink frequency are defined in such a way that interferences are avoided.

4. The method according to claim 2 wherein a frequency hopping method is used.