Application specific integrated circuits for measuring devices

Abstract

An application specific integrated circuit for a measurement device, comprising: a first finite state machine configured to control an external radar chip configured to generate and / or detect radar measurement signals; and a second finite state machine configured to monitor the external radar chip and / or to monitor a processor or memory configured to determine measurements from radar measurement signals detected by the external radar chip.

Description

REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from German Patent Application No. 10 2023 200 484.4, filed January 23, 2023, the entire text of which is incorporated herein by reference. [Technical Field]

[0002] The present invention relates to measurement device technology for process automation in industrial and private environments. In particular, the present invention relates to application specific integrated circuits (ASICs) for measurement devices, measurement devices with application specific integrated circuits, and the use of ASICs for measurement devices. [Background technology]

[0003] Measuring devices for process automation in industrial and private environments may be equipped with radar circuits that generate and emit high-frequency radar measurement signals that are reflected by, for example, the surface of a product or an object to be detected and received by the antenna of the measuring device, allowing the distance to the product surface or object to be calculated.

[0004] Examples of such measuring devices are radar level measuring devices that can be installed inside containers. These radar level measuring devices can be of the free-radiating type or use the guided microwave principle. In the latter case, they are provided with an elongated measuring probe that is inserted into the product.

[0005] The energy supply to such measuring devices is usually obviously limited, for example in the form of a 4-20 mA two-wire line or, especially in the case of stand-alone measuring devices, in the form of a battery. To reduce the energy requirements of such measuring devices, the frequency of measurements can be reduced. However, in this case, changes in levels during measurement pauses will only be recorded at a later point in time. Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the present invention is to provide a radar measurement device that allows for energy-efficient operation and high measurement accuracy. [Means for solving the problem]

[0007] This object is solved by the features of the independent patent claims. Further embodiments of the invention are given by the dependent claims and the following description of embodiments.

[0008] A first aspect of the present disclosure relates to an application specific integrated circuit, ASIC, for a measurement device comprising a first finite state machine and a second finite state machine.

[0009] The first finite state machine is configured to control an external radar chip of the measurement device, the external radar chip configured to generate radar measurement signals and detect measurement signals reflected by an object or product surface. The second finite state machine is configured to monitor the external radar chip and / or a memory of the application specific integrated circuit configured to determine measurements from the radar measurement signals detected by the external radar chip. Additionally or alternatively, the second finite state machine may be configured to monitor the external radar chip and / or a processor of the measurement device configured to determine measurements from the radar measurement signals detected by the external radar chip.

[0010] The measuring device is, for example, a level measuring device, in particular a level radar measuring device, or another radar measuring device.

[0011] The external radar chip is configured to generate radar measurement signals emitted by an antenna or beam element. The processor is configured to determine measurement values ​​from the received radar signals. The external radar chip and the ASIC are separate components and connected to each other via corresponding control and supply lines. Alternatively, the ASIC and the external radar chip may be designed as an integrated component.

[0012] The ASIC can be designed as a radar companion ASIC, which performs control and / or measurement acquisition tasks in the radar circuit of the measurement device. In this way, when using several different radar chips, the essential control and detection tasks can be integrated into a compact unit at low cost, while at the same time enabling energy-efficient operation of the corresponding radar chips.

[0013] According to one embodiment, the ASIC includes a phase locked loop (PLL).

[0014] According to a further embodiment, the ASIC comprises an analog-to-digital converter circuit (ADC).

[0015] According to a further embodiment, the ASIC has a digital interface to the processor.

[0016] According to a further embodiment, the first finite state machine and the second finite state machine are designed as a single component.

[0017] According to a further embodiment, the external radar chip is a radar Monolithic Microwave Integrated Circuit (MMIC).

[0018] According to a further embodiment, the ASIC is configured to wake up the processor from a sleep mode and thereafter transmit the measurement data to the processor.

[0019] According to a further embodiment, the ASIC is configured to power a Voltage-Controlled Oscillator (VCO) of the external radar chip and / or a multiplier of the external radar chip.

[0020] The PLL, ADC, power management and safety functions can all be integrated on the ASIC. In particular, the ASIC can be configured to accommodate different radar chips with different operating frequencies, e.g., 6GHz, 24GHz, 80GHz, 180GHz, 240GHz, etc. To achieve this, a finite state machine can be programmed accordingly.

[0021] The radar chip and ASIC can be optimized with respect to the energy requirements for detecting the echo curve. In particular, parts of the radar chip, ASIC and / or processor can be switched on only when actually needed. Unnecessary circuit parts can be quickly switched off. In particular, the radar circuit can be optimized with respect to size and cost.

[0022] In particular, the radar circuitry of the measurement device can be configured to be powered by a limited energy source (e.g., a 4-20 mA power supply or energy harvesting). A voltage of 3.3 V can be supplied to both the processor and the ASIC. The ASIC can also be configured to support several different supply voltages. The ASIC and radar chip can be located on the same printed circuit board (PCB).

[0023] The radar circuitry, and in particular the ASIC, can be configured to operate in an energy-saving operating mode after the measurement is completed and in particular during the process of determining the measurement value, the nature of which depends on the radar chip used.

[0024] The term "process automation in industrial environments" can be understood as a branch of technology that includes means for operating machines and systems without human intervention. One of the goals of process automation is to automate the interaction of individual components of facilities in industries such as chemical, food, pharmaceutical, petroleum, paper, cement, transportation, or mining. For this purpose, various sensors can be used that are specifically adapted to the specific requirements of the industrial processes, such as mechanical stability, resistance to contamination, extreme temperatures and pressures, etc. The measurements from these sensors are usually transmitted to a control room. In the control room, process parameters such as fill level, limit levels, flow rate, pressure, density, etc. are monitored, and the settings of the entire facility can be changed manually or automatically.

[0025] One area of ​​process automation in industrial environments relates to facility logistics automation and supply chain logistics automation. In logistics automation, distance and angle sensors are used to automate processes inside and outside buildings or within individual logistics systems. Typical applications of logistics automation systems include airport baggage and cargo handling, traffic monitoring (toll systems), retail, parcel delivery, and building security (access control). What these examples have in common is that each application requires the precise measurement of an object's size and position, combined with the ability to detect its presence. For this purpose, sensors based on optical measurement methods using lasers, LEDs, 2D cameras, or 3D cameras, which detect distance according to the time-of-flight (ToF) principle, can be used.

[0026] Another area of ​​process automation in industrial environments is factory / production automation. This application is commonly found in various sectors such as automobile manufacturing, food production, the pharmaceutical industry, packaging, etc. The goal of factory automation is to automate the production of goods using machines, production lines and / or robots, i.e., to operate them without human intervention. The specific requirements regarding the sensors used here and the measurement accuracy in detecting the position and size of objects are similar to those in the logistics automation example mentioned above.

[0027] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. When the same reference numerals are used in the following description of the drawings, they indicate the same or similar elements. The illustrations in the figures are schematic and not to scale.

[0028] A further aspect of the present disclosure relates to a measurement device that includes a radar chip configured to generate and detect radar measurement signals and an application specific integrated circuit, such as those described above and below, located, for example, between the radar chip and a processor.

[0029] A further aspect of the present disclosure relates to the use of the application specific integrated circuits described above and below for a measurement device, in particular a level radar measurement device comprising a radar chip. [Brief explanation of the drawings]

[0030] [Figure 1] The radar MMIC and peripheral circuits using discrete components are shown together with a circuit diagram. [Figure 2] An application specific integrated circuit is presented that can perform control and sensing tasks during the operation of a purely analog MMIC. [Figure 3] 1 shows the configuration of a radar measurement device having an application specific integrated circuit. [Figure 4] The general utility of application specific integrated circuits for the widely used level measurement radar MMIC is demonstrated. [Figure 5] 1 illustrates the overall sequence of a self-test function in an application specific integrated circuit. [Figure 6] This shows part of the test sequence for an externally connected MMIC. [Figure 7] 1 shows a measuring device with a radar circuit. DETAILED DESCRIPTION OF THE INVENTION

[0031] Figure 1 shows a radar MMIC 101 and its peripheral circuitry using discrete components. The radar MMIC generates an 80 GHz radar measurement signal that is transmitted in the direction of the product via an antenna 118. The MMIC has a voltage-controlled oscillator (VCO) 107 that is controlled by an external PLL 104. A TCXO oscillator 115 is provided to control the PLL at a frequency of 40 MHz. The TCXO oscillator 115 also controls the analog-to-digital conversion circuit 105.

[0032] In addition to the VCO 107, the MMIC also comprises a multiplier 108 controlled at 40 GHz by the VCO 107. The multiplier doubles the frequency and controls a Tx amplifier 109 connected to an antenna 118 via a transmit / receive switch, e.g. a circulator. Furthermore, a down converter 110 is provided which receives the signal from the multiplier 108 and the transmit / receive switch.

[0033] All other components are located external to the MMIC. The downconverter 110 sends its signal to an amplifier and filter circuit 113, which sends it to an ADC 105. The ADC 105 is connected to the processor 103 of the measuring device via an SPI interface. The processor 103 can exchange data with an external memory 116. Furthermore, the processor 103 is connected to a fieldbus modem 117 for transmitting the measured values.

[0034] FIG. 2 shows a radar companion ASIC 102 that can take over control and detection tasks during operation of a purely analog MMIC. The ASIC 102 includes a linearization circuit, e.g., an integer or fractional-rational PLL 104, a power supply 111, a self-test circuit 112, e.g., a second finite state machine 112, an amplifier and filter circuit 113 or an IF gain AAF circuit 113, an analog-to-digital conversion circuit 104 (e.g., configured to convert analog signals to digital values ​​with 16-bit accuracy and a 40 MHz sampling frequency), a first-in-first-out (FiFo) memory 114, and a finite state machine 106. The ASIC 102 is a separate component but can be located on the same circuit board as the MMIC 101 (see FIG. 3). FIG. 3 shows a configuration of a radar circuit 100 for a radar measurement device that includes the above-described ASIC 102. The ASIC 102 is connected between the radar chip 101 and the processor 103. Communication between the ASIC 102 and the processor 103 occurs via the FiFo 114 using, for example, a QSPI interface, and from the processor 103 to the FSM 106 via an SPI interface.

[0035] The FSM 106 may be programmed and configured to suit the connected radar chip. The FSM may include hardware units suitable for this purpose. The FSM may in particular consist of a processor that sets the parameters for distance measurements using the frequency-modulated continuous wave (FMCW) method. Depending on the operating frequency of the connected radar chip, the start frequency, stop frequency, duration, transmission power, and / or other parameters of the radar chip to be used in each case can be stored in the FSM 106, for example, according to technical approval specifications. This allows the MMIC 101 to be woken up with an appropriate signal and perform the desired measurements in a later measurement run. In particular, the FSM may have complete control over the MMIC during measurement execution. This means that the intervention or cooperation of the processor core 103 is no longer required. For example, to save energy, the processor core 103 may be switched to a power-saving state by the FSM 106 while radar measurements are being performed and then reactivated by the FSM 106 once the data has been recorded.

[0036] The FSM 106 may further be configured to transmit information about each connected radar chip 101 to the second finite state machine 112. The second finite state machine 112 may also be configured to independently recognize in each case the type of connected MMIC 101. The second finite state machine 112 may use the information about the type of connected MMIC 101 to optimize the self-test sequence and appropriately perform the self-test on the connected MMIC.

[0037] The ASIC 102 supplies power to the VCO 107 and multiplier 108 of the MMIC 101 and can perform or run a self-test on the MMIC 101 (see FIG. 3). In particular, the RC-ASIC 102 can be used to verify the functionality of the MMIC 101. This is particularly useful in SIL applications. The processor 103 may be integrated on the ASIC 102. However, the processor 103 may also be a separate component, as shown in FIG. 3.

[0038] In particular, the MMIC 101 and RC-ASIC 102 can be fabricated using different semiconductor technologies and chip materials. For example, the MMIC can be optimized for use at high frequencies, e.g., 80 GHz or higher, while the RC-ASIC 102 is optimized for significantly lower frequencies, e.g., 40 MHz. This allows for energy savings compared to integrating an ASIC module onto the MMIC.

[0039] Figure 4 shows the general utility of the RC-ASIC 102 for level measurement radar MMICs designed for widely different frequency ranges, e.g., 6 GHz, 24 GHz, 80 GHz, 180 GHz, and 240 GHz.

[0040] 5 shows the overall sequence of the self-test function in the companion ASIC 102. The procedure starts at step 501. In step 502, the radar companion ASIC 102 is configured. In step 503, safety settings are configured. In step 504, the time since the last FiFo memory test is checked to see if it is within a predetermined minimum time t safe It is determined whether the time is longer than

[0041] If not, the procedure continues to step 507. In this case, no testing of the FiFo memory integrated into the radar companion ASIC 102 is necessary.

[0042] If the time since the last FiFo memory test is less than a predetermined minimum time t safe If it is longer, the next step is step 505, where the FiFo memory is internally tested. In step 506, the test results are provided externally.

[0043] In step 507, the time since the last MMIC test is determined to be a predetermined minimum time t MMICsafeIf not, no MMIC testing is required and the procedure proceeds to step 510. If so, MMIC testing is performed in step 508. In step 509, the test results are made available to the outside world.

[0044] Finally, the normal measurement of the measuring device, for example a level measurement, is initiated in step 510. The procedure ends in step 511.

[0045] 6 shows part of a sequence for testing an externally connected MMIC. The procedure starts in step 601. In step 602, a test signal in the kHz range is provided. The measurement sequence in the MMIC begins in step 603. In step 604, measurement data is loaded into FiFo. After the measurement data is loaded into FiFo, the MMIC is shut down in step 605. In step 606, the FiFo data is analyzed against the test signal, and in step 607, it is determined whether the test signal was recorded correctly. If not, the procedure proceeds to step 609, where a status such as "uncertain" is output. If yes, the procedure proceeds to step 608, where a status such as "safe" is output. In step 610, the procedure ends.

[0046] FIG. 7 shows a measuring device 200, such as a radar level measuring device, equipped with the circuit 100 described above, which has a level radar antenna 118 that emits a radar measurement signal and receives the radar measurement signal reflected from the product surface.

[0047] The present disclosure provides a radar companion ASIC that combines essential control and sensing tasks into a compact unit at low cost when using commercially available radar chips, and is specifically adapted to monitor itself and an externally connected commercially available MMIC for reliable operation in accordance with IEC 61508.

[0048] The PLL, ADC, power management functions, and safety functions can be integrated into one chip. In particular, the ASIC can support different radar chips with different operating frequencies and different built-in self-tests (BISTs). The ASIC may be configured to provide corresponding signals to externally indicate a system-wide safe state and / or a system-wide unsafe state.

[0049] The externally provided signal may indicate the current safety state of the radar companion ASIC and / or the externally connected radar MMIC.

[0050] The terms used in the claims should be interpreted to give them the broadest reasonable interpretation consistent with the foregoing. For example, the use of the article "a" or "the" when introducing an element should not be construed as excluding a plurality of elements. Similarly, references to "or" should be construed as including a plurality of elements, and a reference to "A or B" does not exclude "A and B" unless it is clear from the context or the foregoing 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 of the group of elements consisting of A, B, and C, and should not be construed as requiring at least one of each of the listed elements A, B, and C, regardless of whether A, B, and C are combined as a category or the like. Furthermore, references to "A, B, and / or C" or "at least one of A, B, or C" should be construed as including a single unit of the listed elements (e.g., A), a subset of the listed elements (e.g., A and B), or the entire list of elements A, B, and C.

Claims

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

2. 10. The application specific integrated circuit (102) of claim 1, The application specific integrated circuit (102) further comprises a phase locked loop (PLL) (104).

3. 3. An application specific integrated circuit (102) according to claim 1 or 2, comprising: The application specific integrated circuit (102) further comprises an analog-to-digital conversion circuit (ADC) (105).

4. 4. An application specific integrated circuit (102) according to any one of claims 1 to 3, comprising: The application specific integrated circuit (102) further comprises a digital interface to a processor (103) of the measurement device (200).

5. 5. An application specific integrated circuit (102) according to any one of claims 1 to 4, comprising: An application specific integrated circuit (102) in which the first finite state machine (106) and the second finite state machine (112) are implemented as a single component.

6. 6. An application specific integrated circuit (102) according to any one of claims 1 to 5, comprising: The external radar chip (101) is a radar MMIC, an application specific integrated circuit (102).

7. 7. An application specific integrated circuit (102) according to any one of claims 1 to 6, comprising: The application specific integrated circuit (102) is a radar companion ASIC that performs control and / or measurement acquisition tasks for the measurement device (200).

8. 8. An application specific integrated circuit (102) according to any one of claims 1 to 7, comprising: The application specific integrated circuit (102) is configured to wake up the processor (103) from a sleep mode and transmit measurement data to the processor immediately thereafter.

9. 9. An application specific integrated circuit (102) according to any one of claims 1 to 8, comprising: The ASIC (102) is an application specific integrated circuit (102) configured to supply power to a voltage controlled oscillator (VCO) (107) of the external radar chip (101) and / or a multiplier (108) of the external radar chip (101).

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

11. 11. The measuring device (200) of claim 10, A measurement device (200) in which the application specific integrated circuit (102) and the radar chip (101) are separate components.

12. 12. A measuring device (200) according to claim 10 or 11, The measuring device (200) is embodied as a level radar measuring device (200).

13. Use of an application specific integrated circuit (102) according to any one of claims 1 to 9, in particular for a level radar measurement device (200) comprising a radar chip (101).

Images