Application-specific integrated circuit for a measuring device

Abstract

The invention relates to an application-specific integrated circuit for a measuring device, said circuit comprising: a first finite-state machine which is designed to control an external radar chip designed to generate and / or detect a radar measurement signal; and a second finite-state machine which is designed to monitor a memory or processor, that is designed to determine a measurement value from the radar measurement signal detected by the external radar chip, and / or the external radar chip.

Description

[0001] Application-specific integrated circuit for a measuring device

[0002] Reference to related applications

[0003] This application claims priority from German patent application No. 102023200484.4, filed on January 23, 2023, which is incorporated in its entirety by reference into this document.

[0004] Field of the invention

[0005] The present invention relates to measuring device technology for process automation in industrial or private environments. In particular, the invention relates to an application-specific integrated circuit (ASIC) for a measuring device, a measuring device with an application-specific integrated circuit, and a use of an ASIC for a measuring device.

[0006] Technical background

[0007] Measuring devices for process automation in industrial or private environments can incorporate radar circuits that generate and emit a high-frequency radar measurement signal. This radar measurement signal is reflected, for example, by a product surface or an object to be detected and captured by the measuring device's antenna. From this, the distance to the product surface or object can be calculated.

[0008] Examples of such measuring devices include radar level gauges, which can be installed inside a container. These radar level gauges can be free-radiating or use the guided microwave principle. In the latter case, an elongated measuring probe is provided that is immersed in the medium.

[0009] Such measuring devices typically have a very limited power supply, for example, in the form of a 4 to 20 mA two-wire line or, especially in the case of a self-contained measuring device, in the form of a battery. To reduce the power consumption of such a measuring device, the frequency of measurements can be reduced. However, level changes during the measurement pause are then only recorded at a later time.

[0010] Summary

[0011] It is an object of the present invention to provide a radar measuring device which is characterized by energy-efficient operation and high measurement accuracy.

[0012] This object is achieved by the features of the independent patent claims. Further developments of the invention emerge from the subclaims and the following description of embodiments.

[0013] A first aspect of the present disclosure relates to an application specific integrated circuit, ASIC, for a measuring device comprising a first finite state machine and a second finite state machine.

[0014] The first finite state machine is configured to control an external radar chip of the measuring device, which is configured to generate a radar measurement signal and to detect the measurement signal reflected from an object or a product surface. The second finite state machine is configured to monitor a memory of the application-specific integrated circuit, which is configured to determine a measured value from the radar measurement signal detected by an external radar chip, and / or the external radar chip. The second finite state machine can additionally or alternatively be configured to monitor a processor of the measuring device, which is configured to determine a measured value from the radar measurement signal detected by the external radar chip, and / or the external radar chip.

[0015] The measuring device is, for example, a level measuring device, in particular a level radar measuring device, or another radar measuring device.

[0016] The external radar chip is configured to generate a radar measurement signal, which is then radiated by an antenna or a radiating element. The processor is configured to determine a measurement value from the received radar signals. The external radar chip and the ASIC are separate components and are interconnected via corresponding control and supply lines. The ASIC and external radar chip can also be implemented as an integrated component.

[0017] The ASIC can be implemented as a radar companion ASIC, which performs control and / or data acquisition tasks in the radar circuit of the measuring device. This allows essential control and acquisition tasks when using different radar chips to be combined cost-effectively in a compact unit, while simultaneously enabling energy-efficient operation of the corresponding radar chip.

[0018] According to one embodiment, the ASIC comprises a phase locked loop (PLL).

[0019] According to a further embodiment, the ASIC comprises an analog-to-digital converter (ADC) circuit.

[0020] According to a further embodiment, the ASIC has a digital interface to the processor. According to a further embodiment, the first finite state machine and the second finite state machine are implemented as an integrated component.

[0021] According to a further embodiment, the external radar chip is a radar MM IC (Monolithic Microwave Integrated Circuit).

[0022] According to a further embodiment, the ASIC is configured to wake the processor from a sleep mode and then transmit measurement data to the processor.

[0023] According to a further embodiment, the ASIC is configured to supply a voltage controlled oscillator, VCO, of the external radar chip and / or a multiplier of the external radar chip.

[0024] PLL, ADC, power management, and safety functions can all be integrated on the ASIC. In particular, the ASIC can be configured to support various radar chips with different operating frequencies, for example, 6 GHz, 24 GHz, 80 GHz, 180 GHz, and 240 GHz. To achieve this, the finite-state machine can be programmed accordingly.

[0025] The radar chip and ASIC can be optimized with regard to energy consumption for detecting an echo curve. In particular, it can be provided that parts of the radar chip, ASIC, and / or processor are only switched on when they are actually needed. Unneeded circuit components can be quickly switched off. The radar circuit can be optimized, particularly with regard to size and cost.

[0026] In particular, the radar circuit of the measuring device can be configured for power from a limited energy source (e.g., a 4 to 20 mA supply or energy harvesting). A supply voltage of 3.3 V can be provided for both the processor and the ASIC. The ASIC can also be configured for several different supply voltages. The ASIC and the radar chip can be positioned on the same circuit board. The radar circuit and, in particular, the ASIC can be configured to operate in an energy-saving mode after the measurement has been completed, and in particular during the measurement value determination process. The energy-saving mode depends on the radar chip used.

[0027] The term "process automation in industrial environments" can be understood as a branch of technology that includes measures for operating machines and systems without human intervention. One goal of process automation is to automate the interaction of individual components of a plant in the chemical, food, pharmaceutical, petroleum, paper, cement, shipping, or mining industries. A variety of sensors can be used for this purpose, which are specifically adapted to the specific requirements of the process industry, such as mechanical stability, insensitivity to contamination, extreme temperatures, and extreme pressures. Measured values ​​from these sensors are usually transmitted to a control room, where process parameters such as fill level, limit level, flow rate, pressure, or density are monitored, and settings for the entire plant can be changed manually or automatically.

[0028] A sub-area of ​​process automation in the industrial environment concerns the logistics automation of plants and the logistics automation of supply chains. With the help of distance and angle sensors, processes inside or outside a building, or within a single logistics facility, are automated in the field of logistics automation. Typical applications for logistics automation systems include baggage and freight handling at airports, traffic monitoring (toll systems), retail, parcel distribution, and building security (access control). What the aforementioned examples have in common is that the respective application requires presence detection in combination with precise measurement of the size and location of an object.For this purpose, sensors based on optical measuring methods using lasers, LEDs, 2D cameras or 3D cameras that measure distances according to the time of flight (ToF) principle can be used.

[0029] Another sub-area of ​​process automation in the industrial environment concerns factory / production automation. Applications for this can be found in a wide variety of industries, such as automotive manufacturing, food production, the pharmaceutical industry, and packaging in general. The goal of factory automation is to automate the production of goods using machines, production lines, and / or robots, i.e., to run it without human intervention. The sensors used here and the specific requirements regarding measurement accuracy for detecting the position and size of an object are comparable to those in the previous example of logistics automation.

[0030] Embodiments of the present disclosure are described below with reference to the figures. Where the same reference numerals are used in the following description of the figures, they denote identical or similar elements. The representations in the figures are schematic and not to scale.

[0031] A further aspect of the present disclosure relates to a measuring device comprising a radar chip configured to generate and detect a radar measurement signal, and an application-specific integrated circuit as described above and below, which is arranged, for example, between the radar chip and the processor.

[0032] A further aspect of the present disclosure relates to the use of an application-specific integrated circuit described above and below for a measuring device, in particular for a level radar measuring device comprising a radar chip.

[0033] Brief description of the figures Fig. 1 shows a circuit diagram of a radar MMIC with peripheral circuitry using discrete components.

[0034] Fig. 2 shows an application-specific integrated circuit that can perform control and acquisition tasks when operating a purely analog MMIC.

[0035] Fig. 3 shows the structure of a radar measuring device with an application-specific integrated circuit.

[0036] Fig. 4 shows the universal usability of the application-specific integrated circuit for widely used radar MMICs for level measurement.

[0037] Fig. 5 shows the overall sequence of a self-test function in the application-specific integrated circuit.

[0038] Fig. 6 shows a partial test sequence of the externally connected MMIC.

[0039] Fig. 7 shows a measuring device with a radar circuit.

[0040] Detailed description of embodiments

[0041] Fig. 1 shows a radar MMIC 101 with peripheral circuitry consisting of discrete components. The radar MMIC generates an 80 GHz radar measurement signal, which is radiated toward the medium via antenna 118. The MMIC has a voltage-controlled oscillator (VCO) 107, which is controlled by an external PLL 104. A TCXO oscillator 115 is provided, which drives the PLL at a frequency of 40 MHz. The TCXO oscillator 115 also controls the analog-to-digital converter circuit 105.

[0042] In addition to the VCO 107, the MMIC has a multiplier 108, which is driven by the VCO 107 at 40 GHz. The multiplier doubles the frequency and drives the TX amplifier 109, which is connected to the antenna 118 via a transmit / receive combiner, such as a circulator. A downconverter 110 is also provided, which receives signals from the multiplier 108 and the transmit / receive combiner. All other components are located outside the MMIC. The downconverter 110 sends its signal to an amplification and filter circuit 113, which then forwards it to the ADC 105. The ADC 105 is connected to the measuring device's processor 103 via an SPI interface. The processor 103 can exchange data with an external memory 116. In addition, the processor 103 is connected to a fieldbus modem 117 for measured value transmission.

[0043] Fig. 2 shows a radar companion ASIC 102, which can perform control and detection tasks during operation of a purely analog MMIC. The ASIC 102 has a linearization circuit, for example, an integer or fractional rational PLL 104, a power supply 111, a self-test circuit 112, for example in the form of a second finite state machine 112, an amplification and filter circuit 113 or IF Gain AAF circuit 113, an analog-to-digital converter circuit 104 (which is configured, for example, to convert analog signals with an accuracy of 16 bits and a sampling frequency of 40 MHz into digital values), a first-in-first-out (FIFO) memory 114, and a finite state machine 106. The ASIC 102 is a separate component but can be arranged on the same circuit board as the MMIC 101 (see Fig. 3). Fig. 3 shows the structure of a radar circuit 100 for a radar measuring device, which has the ASIC 102 described above.The ASIC 102 is connected between the radar chip 101 and the processor 103. Communication between the ASIC 102 and the processor 103 occurs, for example, via the FIFO 114 using a QSPI interface and, from the processor 103, via an SPI interface to the FSM 106.

[0044] The FSM 106 can be configured to match the connected radar chip. The FSM can include suitable hardware units for this purpose. The FSM can be configured, in particular, by the processor to set the parameters for a distance measurement according to an FMCW method. Depending on the operating frequency of the connected radar chip, it may be necessary, for example due to regulatory requirements, to store the start frequency, stop frequency, duration, transmission power, and / or other parameters of the radar chip used in the FSM 106. This enables the FSM 106 to then enable the MMIC 101 to perform the desired measurement in a subsequent measurement run by controlling it with suitable signals.In particular, it can be provided that the FSM completely controls the MMIC during the execution of a measurement, thus eliminating the need for intervention or cooperation by the processor core 103. For example, to save energy, the processor core 103 can be transferred to a power-saving state by the FSM 106 while a radar measurement is being performed, and can be reactivated after the FSM 106 has completed the data acquisition.

[0045] The FSM 106 can further be configured to forward the information about the respectively connected radar chip 101 to the second finite state machine 112. It can also be provided that the second finite state machine 112 is configured to independently detect the type of the respectively connected MMIC 101. The second finite state machine 112 can use the information about the type of the connected MMIC 101 to optimize a self-test sequence and execute it appropriately for the connected MMIC.

[0046] The ASIC 102 can supply power to the VCO 107 and the multiplier 108 of the MMIC 101 and perform or trigger a self-test of the MMIC 101 (see Fig. 3). In particular, the RC-ASIC 102 can be used to test the functionality of the MMIC 101. This is particularly advantageous for SIL applications. The processor 103 can be integrated into the ASIC 102. However, it can also be a separate component, as shown in Fig. 3.

[0047] In particular, the MMIC 101 and the RC-ASIC 102 can be manufactured using different semiconductor technologies and chip materials. Thus, the MMIC can be optimized for use at high frequencies, for example, 80 GHz or higher, whereas the RC-ASIC 102 is optimized for applications at significantly lower frequencies, for example, 40 MHz. This can save energy compared to integrating the ASIC module on an MMIC. Fig. 4 shows the universal usability of the RC-ASIC 102 for radar MMICs for level measurement, which are designed for very different frequency ranges, for example, 6 GHz, 24 GHz, 80 GHz, 180 GHz, and 240 GHz.

[0048] Fig. 5 shows the overall sequence of a self-test function in the companion ASIC 102. The method starts with step 501. In step 502, the radar companion ASIC 102 is configured. In step 503, the safety setup is configured. In step 504, it is determined whether the time since the last FIFO memory test is greater than a predeterminable minimum time period tsafe.

[0049] If this is not the case, the method continues with step 507. In this case, no test of the FIFO memory integrated in the Radar Companion ASIC 102 is necessary.

[0050] If the time since the last FIFO memory test is greater than a predefined minimum time period tsafe, the next step is step 505, in which the FIFO memory is tested internally. In step 506, the test result is then made available externally.

[0051] In step 507, a determination is made as to whether the time since the last MMIC test is greater than a predeterminable minimum time period tMMicsafe. If this is not the case, the method jumps to step 510, since no MMIC test is necessary. If this is the case, step 508 follows, in which an MMIC test is performed. In step 509, the test result is then provided externally.

[0052] Finally, in step 510, the measuring device's normal measurement is started, for example, a fill level measurement. The method ends in step 511.

[0053] Fig. 6 shows the partial sequence of a test of the externally connected MMIC. The method starts with step 601. In step 602, a test signal in the kHz range is provided. In step 603, the measurement sequence in the MMIC starts. In step 604, the measurement data is read into the FIFO, and in step 605, the MMIC is deactivated. In step 606, the FIFO data is analyzed for the test signal, and in step 607, it is determined whether the test signal was acquired correctly. If this is not the case, the method jumps to step 609, where the status "uncertain" or something similar is output. If this is indeed the case, the method jumps to step 608, where the status "safe" or something similar is output. The method then ends with step 610.

[0054] Fig. 7 shows a measuring device 200, for example a radar level measuring device, with the circuit 100 described above, which has a level radar antenna 118 for emitting the radar measurement signal and for receiving the radar measurement signal reflected at the surface of the filling material.

[0055] The present disclosure provides a radar companion ASIC that combines essential control and detection tasks when using commercial radar chips in a compact unit at low cost, and is particularly configured to monitor itself and an externally connected commercially available MMIC for reliable operation according to IEC61508.

[0056] PLL, ADC, power management, and safety functions can be combined in a single chip. In particular, the ASIC can support various radar chips with different operating frequencies and different built-in self-tests (BIST). The ASIC can be configured to provide a corresponding signal that externally indicates the safe state of the overall system and / or an unsafe state of the overall system.

[0057] The signal provided externally can be indicative of the current security status of the Radar Companion ASIC and / or the externally connected Radar MMIC.

[0058] The terms used in the claims should be construed to give them the broadest possible reasonable interpretation consistent with the foregoing description. For example, the use of the article "a" or "the" in introducing an element should not be construed to exclude a plurality of elements. Likewise, the mention of "or" should be construed to include a plurality of elements, so that the mention of "A or B" does not exclude "A and B" unless it is clear from the context or the preceding description that only one of A and B is intended.Furthermore, the phrase "at least one of A, B, and C" should be understood as one or more elements from a group of elements consisting of A, B, and C, and should not be interpreted as requiring at least one of each of the listed elements A, B, and C, whether A, B, and C are related as categories or otherwise. Furthermore, the reference to "A, B, and / or C" or "at least one of A, B, or C" should be interpreted to include each individual unit of the listed elements, e.g., A, each subset of the listed elements, e.g., A and B, or the entire list of elements A, B, and C.

Claims

Patent claims 1. An application-specific integrated circuit (102) for a measuring device (200), comprising: a first finite state machine (106) configured to control an external radar chip (101) configured to generate and / or detect a radar measurement signal; a second finite state machine (112) configured to monitor a memory (114) of the application-specific integrated circuit (102), which is configured to determine a measured value from the radar measurement signal detected by the external radar chip (101), and / or to monitor the external radar chip.

2. Application-specific integrated circuit (102) according to claim 1, wherein the application-specific integrated circuit (102), ASIC, comprises a phase-locked loop (104), PLL.

3. Application-specific integrated circuit (102) according to claim 1 or 2, wherein the ASIC (102) comprises an analog-to-digital converter circuit (105), ADC.

4. Application-specific integrated circuit (102) according to one of the preceding claims, wherein the ASIC (102) has a digital interface to a processor (103) of the measuring device (200).

5. Application-specific integrated circuit (102) according to one of the preceding claims, wherein the first finite state machine (106) and the second finite state machine (112) are implemented as an integrated component.

6. Application-specific integrated circuit (102) according to one of the preceding claims, wherein the external radar chip (101) is a radar MMIC.

7. Application-specific integrated circuit (102) according to one of the preceding claims, wherein the ASIC (102) is a radar companion ASIC which performs control tasks and / or measured value acquisition tasks of the measuring device (200).

8. Application-specific integrated circuit (102) according to one of the preceding claims, wherein the ASIC (102) is configured to wake the processor (103) from a sleep mode and then transmit measurement data to the processor.

9. Application-specific integrated circuit (102) according to one of the preceding claims, wherein the ASIC (102) is configured to supply a voltage-controlled oscillator (107), VCO, of the external radar chip (101) and / or a multiplier (108) of the external radar chip.

10. A measuring device (200) comprising: a radar chip (101) configured to generate a radar measurement signal; an application-specific integrated circuit (102), ASIC, according to one of claims 1 to 9.

11. The measuring device (200) of claim 10, wherein the ASIC and the radar chip are separate components.

12. Measuring device (200) according to claim 10 or 11, designed as a level radar measuring device (200) 13. Use of an application-specific integrated circuit (102), ASIC, according to one of claims 1 to 9 for a measuring device, in particular for a level radar measuring device (200) having a radar chip (101).

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