Simulation device and method for thermistor in analog ratio type temperature measurement link

Abstract

The application relates to a simulation device and method for simulating a thermistor in a simulated ratio type temperature measurement link. The device comprises a resistance output module, a temporary charge and discharge module and a control module; the resistance output module is connected with a measurement node and is used for outputting a target resistance value of a simulated thermistor; the temporary charge and discharge module is connected with the measurement node and is used for charging or discharging a filter capacitor when the resistance value is switched; the control module is connected with the resistance output module and the temporary charge and discharge module respectively, is used for calculating the target resistance value according to an externally input target temperature, and controls the resistance output module to switch the resistance value and controls the conduction state of the temporary charge and discharge module. By adopting the device, the stable time of the voltage of the measurement node during resistance value switching can be quickly shortened, sampling pollution can be avoided, and the temperature measurement simulation precision and the link stability can be ensured.

Description

Technical Field

[0001] This application relates to the field of battery management system technology, and in particular to a simulation device and method for simulating a thermistor in a ratiometric temperature measurement link. Background Technology

[0002] In fields such as new energy vehicles and energy storage systems, battery management systems (BMS) require precise monitoring of battery temperature to ensure safety and performance. A common approach is to use a ratiometric temperature sensing link. This link typically includes a reference voltage source, a pull-up resistor, a negative temperature coefficient (NTC) thermistor, and a filter capacitor connected in parallel at the measurement node. The BMS's analog-to-digital converter (ADC) calculates the temperature by measuring the ratio of the node voltage to the reference voltage.

[0003] When conducting R&D testing, production verification, or fault diagnosis of the temperature measurement function of a BMS, a simulation device is needed to replace the actual thermistor and flexibly simulate its resistance value under different temperature conditions. Currently, general-purpose programmable resistor boxes or resistance simulation devices are commonly used. However, when such general-purpose devices are connected to a ratiometric temperature measurement link, the NTC has a high resistance value when simulating low-temperature scenarios and switching resistance values. Due to the presence of filter capacitors in the temperature measurement link, the voltage at the measurement node requires a long stabilization time, which can easily exceed the fixed sampling window of the BMS. This leads to the BMS acquiring incorrect transient voltages, making it impossible to quickly and accurately simulate the resistance change process of the thermistor, resulting in temperature measurement errors. Summary of the Invention

[0004] Therefore, it is necessary to provide a simulation device for thermistors in a ratio-type temperature measurement link to address the technical problems mentioned above, such as slow voltage stabilization at the measurement node during resistance switching and the resulting sampling errors.

[0005] Firstly, this application provides a simulation device for a thermistor in a ratiometric temperature measurement link, applicable to a ratiometric temperature measurement link, wherein the ratiometric temperature measurement link includes a reference voltage source, a thermistor, and a filter capacitor connected in parallel at the measurement node, and the device includes a resistor output module, a temporary charge / discharge module, and a control module:

[0006] The resistance output module is connected to the measurement node and is used to output the target resistance value simulating the thermistor;

[0007] The temporary charge / discharge module is connected to the measurement node and is used to charge or discharge the filter capacitor when the resistance value is switched.

[0008] The control module is connected to the resistor output module and the temporary charge / discharge module respectively, and is used to calculate the target resistance value according to the target temperature input by the outside, control the resistor output module to switch the corresponding resistance value, and control the conduction state of the temporary charge / discharge module.

[0009] In one embodiment, the temporary charge / discharge module includes an up-pull branch and a down-pull branch; the up-pull branch is connected between the measurement node and the reference voltage source;

[0010] The pull-down branch is connected between the measurement node and the ground;

[0011] The control module selectively activates the pull-up branch to charge the filter capacitor or activates the pull-down branch to discharge the filter capacitor based on the difference between the target resistance value and the current resistance value.

[0012] In one embodiment, the control module is configured to:

[0013] Before the resistance output module switches the resistance value, the temporary charge / discharge module is turned on;

[0014] After the resistance value is switched, the temporary charging and discharging module is kept on for a first preset duration;

[0015] Disconnect the temporary charge / discharge module and wait for a second preset time period to allow the voltage of the measurement node to enter the target stable range.

[0016] In one embodiment, the resistor output module includes multiple interlocking groups with different resistance values, and each interlocking group includes multiple resistors and multiple switches;

[0017] When switching the switch states within the same interlock group, the control module performs a switching operation that first closes the target switch and then opens the non-target switch, and performs the switching operation on multiple interlock groups in a preset order.

[0018] In one embodiment, the device further includes a bypass switch;

[0019] The bypass switch is connected in parallel across the two ends of the interlock group whose resistance value is higher than the first resistance value, and is connected to the control module.

[0020] The control module is configured to turn on the bypass switch when the target resistance value is less than or equal to the second resistance value.

[0021] In one embodiment, between switching operations of two adjacent interlock groups, the control module controls the temporary charging / discharging module to conduct for a third preset duration.

[0022] In one embodiment, the control module further includes a stability determination submodule;

[0023] The stability judgment submodule is used to obtain the actual voltage of the measurement node and adjust the target resistance value of the resistor output module according to the actual voltage until the preset stability condition is met.

[0024] In one embodiment, the control module further includes a resistance calculation submodule;

[0025] The resistance calculation submodule is used to calculate the target resistance based on the target temperature according to the temperature-resistance correspondence and interpolation rules consistent with the thermistor.

[0026] Secondly, this application also provides a simulation method for a thermistor in a ratiometric temperature measurement link, applicable to the device described in the first aspect, comprising:

[0027] Calculate the target resistance value based on the target temperature;

[0028] The resistor output module is controlled to switch the corresponding resistance value. When the resistance value is switched, the temporary charge and discharge module is controlled to charge or discharge the filter capacitor.

[0029] In one embodiment, controlling the temporary charge / discharge module to charge or discharge the filter capacitor during the resistance value switching includes:

[0030] Before the resistance output module switches the resistance value, the temporary charge / discharge module is turned on;

[0031] After the resistance value is switched, the temporary charging and discharging module is kept on for a first preset duration;

[0032] Disconnect the temporary charge / discharge module and wait for a second preset time period to allow the voltage of the measurement node to enter the target stable range.

[0033] The above-mentioned simulation device and method for simulating the thermistor in a ratio-type temperature measurement link simulates the resistance value of the thermistor through a resistance output module. Combined with the rapid charging and discharging of the filter capacitor by the temporary charging and discharging module during resistance value switching, it effectively solves the problems of voltage lag and long stabilization time of the measurement node caused by the charging and discharging of the filter capacitor in the existing ratio-type temperature measurement link simulation technology, and significantly improves the testing efficiency and reliability of the ratio-type temperature measurement link. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a circuit diagram of a ratiometric temperature sensing link in one embodiment;

[0036] Figure 2 This is a schematic diagram of a simulation device for a thermistor in a ratiometric temperature measurement link in one embodiment.

[0037] Figure 3 This is a schematic diagram of a bypass switch in one embodiment;

[0038] Figure 4 This is a timing diagram for target resistance value switching in one embodiment;

[0039] Figure 5 This is a structural block diagram of the control module in one embodiment;

[0040] Figure 6 This is a flowchart of a switching method for an interlock group in one embodiment. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0042] The simulation device for thermistors in a ratiometric temperature measurement link provided in this application embodiment is applied in a ratiometric temperature measurement link. Figure 1 As shown, this ratiometric temperature measurement link includes a reference voltage source Vref, a pull-up resistor Rup, a thermistor Rntc, and a filter capacitor Cnode connected in parallel at the measurement node. A voltage divider circuit is formed by the reference voltage source Vref, the pull-up resistor Rup, and the thermistor Rntc. The voltage value Vnode at the measurement node is determined by the ratio of the pull-up resistor Rup to the thermistor Rntc, i.e.:

[0043] Vnode = Vref×Rntc / (Rup + Rntc).

[0044] The analog-to-digital converter (ADC) simultaneously samples Vnode and Vref, and calculates their ratio to obtain the value of Rntc. Then, based on the pre-stored temperature-resistance characteristic relationship of the thermistor, the temperature value can be obtained. This ratio measurement method effectively suppresses measurement errors caused by fluctuations in the reference voltage itself. The filter capacitor Cnode is connected in parallel between the measurement node and ground GND to filter out high-frequency noise in the circuit.

[0045] This solution provides a simulation device for a thermistor in a ratiometric temperature measurement link, used to replace a real thermistor in the link and simulate its resistance characteristics at different temperatures. Figure 2 The diagram shown is a structural block diagram of the simulation device, which includes:

[0046] The resistance output module 110 is connected to the measurement node and is used to output the target resistance value of the analog thermistor.

[0047] This module typically consists of a resistor array and a switch network, with the resistors and switches connected according to a specific topology. One end of the module is connected to the measurement node, and the other end is grounded. By driving different combinations of switches to open and close via the control module 130, their equivalent parallel resistance to ground can be changed, thereby synthesizing the desired target resistance value. The target resistance value is calculated by the control module 130 based on the externally input target temperature and according to certain rules.

[0048] The temporary charge / discharge module 120 is connected to the measurement node and is used to charge or discharge the filter capacitor when the resistance value changes.

[0049] This module can be composed of a charging / discharging path including a switch and a current-limiting resistor. Further, to charge or discharge the filter capacitor, this charging / discharging path can include two independent branches: a pull-up branch and a pull-down branch. Each branch consists of a controlled switch and a current-limiting resistor connected in series. The pull-up branch is connected between the measurement node and the reference voltage source, and the pull-down branch is connected between the measurement node and ground. The control module selectively activates the pull-up branch to charge the filter capacitor or activates the pull-down branch to discharge the filter capacitor based on the difference between the target resistance value and the current resistance value.

[0050] The control module 130 is connected to the resistor output module and the temporary charge / discharge module respectively. It is used to calculate the target resistance value based on the target temperature input from the outside, control the resistor output module to switch the corresponding resistance value, and control the conduction state of the temporary charge / discharge module.

[0051] This module can be a processing unit such as a microcontroller unit (MCU), central processing unit (CPU), digital signal processor (DSP), or programmable logic device, as well as necessary memory, input / output interfaces, and driver circuits. This module connects to the resistor output module and the temporary charge / discharge module, respectively. It receives target commands with temperature as the semantic meaning from the host computer or operating interface, calculates the target resistance value, and is responsible for controlling the resistor output module to switch the corresponding resistance value, as well as controlling the conduction state of the temporary charge / discharge module.

[0052] In an exemplary embodiment, when the target resistance value changes, the control module 130 first calculates the target resistance value based on a preset temperature-resistance characteristic curve. Before the resistance output module switches the resistance value, the control module 130 controls the temporary charge-discharge module to pre-charge and discharge the filter capacitor of the measurement node, thereby reducing the difference between the current voltage of the filter capacitor and the voltage corresponding to the target resistance value in advance. This solves the problem of excessive initial voltage difference and excessively long subsequent voltage stabilization time caused by directly switching the resistance value. At the same time, the pre-charge-discharge can also suppress the voltage jump at the moment of resistance value switching.

[0053] Next, the control module 130 controls the resistor output module 110 to switch to the target resistance value. After the resistance value switch, the temporary charge / discharge module is kept on for a first preset duration. This first preset duration is adjustable and adapted to the discharge characteristics of the filter capacitor. After the pre-charge / discharge, the node voltage may still experience slight changes during the resistance value switch. Therefore, the temporary charge / discharge module is not directly disconnected; instead, the first preset duration is maintained to compensate for this shift through rapid charge / discharge, ensuring that the voltage quickly approaches the target stable range. For example, the first preset duration can be set to 1ms to 3ms; this embodiment does not limit its specific value.

[0054] Then, the control module 130 controls the temporary charge / discharge module 120 to disconnect and waits for a second preset time to allow the voltage of the measurement node to enter the target stable range. Since the RC circuit formed by the filter capacitor and the equivalent resistance of the link will experience brief voltage fluctuations after the temporary charge / discharge module is disconnected, and if a multiplexer is present in the circuit, this component may also have residual switching noise, a second preset time is designed to avoid voltage fluctuations. At this time, the measurement node outputs a stable voltage corresponding to the target resistance value, which can be acquired by the ratiometric temperature measurement link. Optionally, the second preset time can be set to ≥2ms, and can be adjusted according to the parameters of the RC circuit and the model of the multiplexer.

[0055] To facilitate understanding, the above embodiment will be described below with reference to the specific circuit parameters of the ratio-type temperature sensing link. Specifically, in the ratio-type temperature sensing link of this embodiment, the thermistor is a negative temperature coefficient (NTC) thermistor, and its resistance is much larger than that of the pull-up resistor.

[0056] Without the temporary charge / discharge module of this scheme, the equivalent time constant τ of the measurement node is approximately equal to the parallel value of the pull-up resistor Rup and the equivalent thermistor Rntc, multiplied by the filter capacitor Cnode, i.e., τ≈(Rup∥Rntc)·Cnode. This is because Rntc in the low-resistance, high-temperature region... Therefore, the equivalent time constant can be simplified to τ≈Rup·Cnode.

[0057] Taking a pull-up resistor Rup = 470kΩ and a filter capacitor Cnode = 100nF as an example, substituting the values, we can calculate the equivalent time constant τ ≈ 470kΩ × 100nF = 47ms. Based on the charging and discharging characteristics of the RC circuit, the time required for the measured node voltage to reach approximately 99% of its steady-state value is about 235ms. However, in actual battery management systems, the sampling window is typically around 50ms. Therefore, the aforementioned 235ms convergence time far exceeds the sampling window duration, leading to sampling contamination and affecting temperature measurement accuracy.

[0058] After introducing the temporary charge / discharge module, the equivalent time constant of the measurement node is determined by the equivalent resistance Rfast of the temporary charge / discharge module and the filter capacitor Cnode, i.e., τ_fast≈Rfast·Cnode. The temporary charge / discharge module adopts a low-impedance design, and its equivalent resistance Rfast can be selected within the range of 2.2kΩ~4.7kΩ. Combined with the aforementioned 100nF filter capacitor Cnode, the range of the equivalent time constant τ_fast after introducing the temporary charge / discharge module is calculated to be: 2.2kΩ×100nF≈0.22ms, 4.7kΩ×100nF≈0.47ms. The time required for the measurement node voltage to reach approximately 99% of its steady-state value is 1.1ms~2.35ms, significantly shortening the convergence time.

[0059] In the above embodiments, by adding a temporary charge and discharge module, the rapid charge and discharge of the filter capacitor in the ratio-type temperature measurement circuit is realized, which improves the simulation response speed and solves the problem of inaccurate temperature measurement caused by the voltage lag of the filter capacitor in the existing resistance simulation technology.

[0060] In one embodiment, the resistor output module 110 includes multiple interlock groups with different resistance values. Each interlock group includes multiple resistors and multiple switches. When switching the switch state within the same interlock group, the control module performs a switching operation of first closing the target switch and then opening the non-target switch, and performs the switching operation on multiple interlock groups in a preset order.

[0061] Specifically, the resistor array and switch network in the resistor output module 110 are divided into multiple interlock groups. The interlock groups are divided based on the magnitude of the equivalent resistance that can be output. Resistors belonging to the same interlock group have nominal resistance values ​​within the same order of magnitude. For example, for interlock groups G1, G2, ..., Gm, G1 corresponds to a resistance of 10Ω, G2 to 100Ω, G3 to 1000Ω, and so on. One feasible connection method is that each interlock group contains multiple parallel resistor branches, and each branch consists of a switch and a resistor connected in series.

[0062] Before switching the target resistance value, the control module first determines the target switch and non-target switch within each interlock group.

[0063] For example, to avoid the repetitive operation of resetting all switches to their default states and then reconfiguring them to the target state every time a switch needs to be switched, the control module performs a minimum switching action when switching switches within the same interlock group from the current state S_current to S_target. Specifically, the control module can represent S_current and S_target as multiple arrays composed of "0" and "1", where "0" represents a switch open and "1" represents a switch closed. An XOR operation is performed on S_current and S_target, and the calculated ΔS is the minimum switching ΔS. Switches with a corresponding bit of 1 in ΔS and a bit of 1 in S_target are the switches that should be on in the target state but are off in the current state; these are the target switches. Switches with a corresponding bit of 1 in ΔS and a bit of 1 in S_current are the non-target switches.

[0064] After identifying the target switch and the non-target switch, the control module first closes the target switch. At this time, both the old and new switches may be turned on simultaneously, but the circuit has at least one low-impedance path to avoid an open circuit. To cover control signal refresh and switch action time, a preset confirmation time is required to ensure the switch is turned on before the non-target switch is opened.

[0065] When the target resistance change involves multiple orders of magnitude, the control module performs the above switching operation on each interlock group in a preset order. For example, it first switches the higher order of magnitude group that has a greater impact on the resistance, and then switches them in descending order.

[0066] In one embodiment, between switching operations of adjacent interlock groups, the control module also controls the temporary charging / discharging module to be turned on for a third preset duration. This step is used to insert a short-term on-time control of the temporary charging / discharging module, such as a pulse lasting 0.3ms to 0.8ms, to suppress voltage jumps that may occur due to a jump in resistance value.

[0067] The interlock group design in this embodiment can achieve fast, glitch-free, and highly reliable resistance switching, solving the problem of voltage disturbance at measurement nodes caused by switching timing or open circuit moment during dynamic switching of general resistor arrays.

[0068] In another embodiment, such as Figure 3 As shown, it also includes a bypass switch 140, which is used to further improve accuracy and stability when simulating low resistance values ​​for short-circuit and micro-ohm level faults.

[0069] Specifically, the bypass switch 140 is connected in parallel across the interlocking group with a resistance value higher than the first resistance value, and is connected to the control module. The control module 130 is also configured to control the bypass switch 140 to conduct when the target resistance value is less than or equal to the second resistance value.

[0070] The first resistance value is set to a value whose nominal resistance in the interlock group is orders of magnitude higher than a preset threshold. When performing a low-resistance simulation with a resistance value lower than the second resistance value, since the high-resistance interlock group is not used, its internal switches still have shutdown leakage current and parasitic capacitance. Therefore, to avoid introducing errors, the high-resistance branch is bypassed by closing the bypass switch 140.

[0071] In a detailed embodiment, the resistance simulation device includes the aforementioned bypass switch 140, the resistance output module 110 is composed of multiple interlock groups, and the timing diagram of the control module 130 controlling each module to perform a target resistance value switching is shown in the figure. Figure 4 As shown.

[0072] The four signal channels in the diagram, from left to right, are the bypass channel BP, the fast charge / discharge channel FS, the resistor output module channel SW, and the measurement node voltage VN.

[0073] In the initial steady state, both the bypass channel BP and the fast charge / discharge channel FS remain at a low level, the switching network maintains its current switching state, and the measured node voltage VN is in a stable output state. When an update is triggered, the control module first determines whether the bypass switch needs to be turned on based on the target resistance value Rset. Then, FS outputs a high-level main pulse of 1.5~2.5ms to start the temporary charge / discharge path. At this time, the switching network enters the preparation switching state, and the measured node voltage quickly approaches the target value, preparing for the pre-charge / discharge process for subsequent resistance value switching.

[0074] Upon entering the intra-group switching phase, the switching network first performs an intra-group connection action, turning on the new switch corresponding to the target resistor. It waits for Xμs or at least one I / O refresh cycle to confirm the stability of the new path before disconnecting the switch corresponding to the old resistor. There are no open-circuit states throughout the entire process. After the switching is completed, FS is pulled back to LOW level, disconnecting the temporary charging and discharging path, and the switching network maintains the new stable state.

[0075] Finally, the system enters a static stabilization phase, waiting for a t_settle time of ≥2ms to cover the transient margin of the RC loop and multiplexer, ensuring that the voltage at the measurement node fully enters the target stable range. Ultimately, all signals remain stable, awaiting the next update trigger. The entire timing design effectively suppresses voltage jumps and significantly shortens the voltage convergence time in the high-resistivity temperature region through short-term FS activation and interlocking switching of the switching network.

[0076] In one embodiment, the control module 130 further includes a stability judgment submodule 131 for implementing closed-loop control of the simulation output. This stability judgment submodule 131 acquires the actual voltage of the measurement node and adjusts the target resistance value of the resistor output module based on the actual voltage until a preset stability condition is met.

[0077] Specifically, this module acquires the actual voltage of the measurement node through a built-in ADC or communication interface and evaluates it based on several preset stability conditions. These stability conditions include calculating the actual voltage ratio ρ_meas and determining whether its error compared to the theoretical ratio is less than a threshold; or converting ρ_meas to the actual temperature T_meas and determining whether its difference from the target temperature is less than a threshold; or it can be converted back to the actual resistance R_meas for judgment. If the stability conditions are not met, iterative adjustment is triggered, and after executing a complete control cycle, stability is assessed again until the stability conditions are met.

[0078] In the above embodiments, closed-loop control through iterative cycles can compensate for resistance errors caused by non-ideal factors and improve simulation accuracy.

[0079] In one embodiment, the control module 130 further includes a resistance calculation submodule 132, which is used to calculate the target resistance value based on the target temperature according to the temperature-resistance correspondence and interpolation rules consistent with the thermistor.

[0080] The temperature-resistance correspondence can be obtained from the datasheet or experimental data of a real thermistor. This correspondence can be a discrete data pair. Because the stored data is usually discrete, the resistance calculation submodule 132 also uses a preset interpolation rule to calculate the resistance corresponding to any continuous target temperature; this interpolation rule.

[0081] In one embodiment, such as Figure 5As shown, the control module 130 includes a stability judgment submodule 131 and a resistance calculation submodule 132. The resistance calculation submodule 132 receives the target temperature input from the host computer, calculates the target resistance value based on the temperature-resistance characteristics and interpolation rules consistent with the actual thermistor, and outputs it to the resistance output module 110 to perform resistance value switching. The stability judgment submodule 131 collects the voltage of the measurement node in real time and compares it with the target voltage. When the deviation between the actual value and the target value exceeds a threshold, the resistance value of the resistance output module 110 is finely adjusted until the voltage enters the target stable range. This dual-module collaborative design improves the accuracy of the simulated resistance value and the voltage stability.

[0082] Specifically, upon receiving the target temperature input from the outside, the resistance calculation module first looks up the temperature-resistance table to locate the range of the target temperature, and then performs calculations according to the preset difference rules. If the target temperature exceeds the range of the table, it performs calculations according to the preset boundary processing rules.

[0083] The aforementioned resistance calculation submodule can eliminate system errors introduced by inconsistent calculation rules, ensuring that the output resistance value is consistent with the measurement logic of the system under test.

[0084] The various modules in the simulation device for the thermistors in the aforementioned analog ratio-type temperature measurement link can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0085] Based on the same inventive concept, this application also provides a simulation method for a thermistor in a simulated ratio-type temperature measurement link, used to implement the simulation device for the thermistor in the simulated ratio-type temperature measurement link described above. The solution provided by this method is similar to the implementation described in the above method. Therefore, the specific limitations in one or more embodiments of the simulation method for thermistors in a simulated ratio-type temperature measurement link provided below can be found in the limitations of the simulation device for the thermistor in a simulated ratio-type temperature measurement link described above, and will not be repeated here.

[0086] In one exemplary embodiment, a simulation method for a thermistor in a ratiometric temperature sensing link is provided. The method includes the following steps:

[0087] Step S201: Calculate the target resistance value based on the target temperature.

[0088] In step S202, the control resistor output module switches the corresponding resistance value. During the resistance value switching, the control temporary charge / discharge module charges or discharges the filter capacitor.

[0089] In one embodiment, controlling the temporary charge / discharge module to charge or discharge the filter capacitor during resistance switching includes the following steps:

[0090] Step S301: Before the resistance output module switches the resistance value, the temporary charge / discharge module is turned on.

[0091] Step S302: After the resistance value is switched, the temporary charging and discharging module is kept on for a first preset duration.

[0092] Step S303: Disconnect the temporary charge / discharge module and wait for the second preset time to allow the voltage of the measurement node to enter the target stable range.

[0093] In one embodiment, the resistor output module is divided into multiple interlocking groups G1, G2, ..., Gm with different resistance values. For example... Figure 6 As shown, the process for performing a minimum handover of an interlock group includes the following steps:

[0094] Step S401: Read S_current and S_target.

[0095] Specifically, the control module represents S_current and S_target as multiple arrays consisting of "0" and "1", where "0" represents the switch being open and "1" represents the switch being closed.

[0096] Step S402, calculate ΔS.

[0097] Perform an XOR operation on S_current and S_target to calculate ΔS, which is the minimum switching ΔS. Switches with a corresponding bit of 1 in ΔS and 1 in S_target are target switches that should be on in the target state but are off in the current state. Switches with a corresponding bit of 1 in ΔS and 1 in S_current are non-target switches.

[0098] Step S403: Select interlock group Gi. Where i∈[1,m].

[0099] Step S404: Turn on the target switch within the interlock group.

[0100] Step S405: After writing the control word, wait for the preset confirmation time.

[0101] Step S406: Disconnect the non-target switch in Gi.

[0102] Step S407: Determine if there is a next group.

[0103] If there is another interlock group that needs to perform resistance value switching, proceed to step S403; otherwise, end the target resistance value switching process.

[0104] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0105] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0106] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0107] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A simulation device for simulating a thermistor in a ratiometric temperature measurement link, applied to a ratiometric temperature measurement link, wherein the ratiometric temperature measurement link includes a reference voltage source, a thermistor, and a filter capacitor connected in parallel at the measurement node, characterized in that, The device includes a resistor output module, a temporary charge / discharge module, and a control module; The resistance output module is connected to the measurement node and is used to output the target resistance value simulating the thermistor; The temporary charge / discharge module is connected to the measurement node and is used to charge or discharge the filter capacitor when the resistance value is switched. The control module is connected to the resistor output module and the temporary charge / discharge module respectively, and is used to calculate the target resistance value according to the target temperature input by the outside, control the resistor output module to switch the corresponding resistance value, and control the conduction state of the temporary charge / discharge module. The control of the resistor output module to switch the corresponding resistance value and the control of the conduction state of the temporary charging and discharging module include: turning on the temporary charging and discharging module before the resistor output module switches the resistance value; maintaining the temporary charging and discharging module on for a first preset duration after the resistance value switch; turning off the temporary charging and discharging module and waiting for a second preset duration so that the voltage of the measurement node enters the target stable range.

2. The apparatus according to claim 1, characterized in that, The temporary charging / discharging module includes an upward branch and a downward branch; The pull-up branch is connected between the measuring node and the reference voltage source; The pull-down branch is connected between the measurement node and the ground; The control module selectively activates the pull-up branch to charge the filter capacitor or activates the pull-down branch to discharge the filter capacitor based on the difference between the target resistance value and the current resistance value.

3. The apparatus according to claim 1, characterized in that, The resistor output module includes multiple interlocking groups with different resistance values, and each interlocking group includes multiple resistors and multiple switches. When switching the switch states within the same interlock group, the control module performs a switching operation that first closes the target switch and then opens the non-target switch, and performs the switching operation on multiple interlock groups in a preset order.

4. The apparatus according to claim 3, characterized in that, The device also includes a bypass switch; The bypass switch is connected in parallel across the two ends of the interlock group whose resistance value is higher than the first resistance value, and is connected to the control module. The control module is configured to turn on the bypass switch when the target resistance value is less than or equal to the second resistance value.

5. The apparatus according to claim 3, characterized in that, Between the switching operations of two adjacent interlock groups, the control module controls the temporary charging and discharging module to be turned on for a third preset duration.

6. The apparatus according to claim 1, characterized in that, The control module also includes a stability judgment submodule; The stability judgment submodule is used to obtain the actual voltage of the measurement node and adjust the target resistance value of the resistor output module according to the actual voltage until the preset stability condition is met.

7. The apparatus according to claim 1, characterized in that, The control module also includes a resistance calculation submodule; The resistance calculation submodule is used to calculate the target resistance based on the target temperature according to the temperature-resistance correspondence and interpolation rules consistent with the thermistor.

8. A simulation method for a thermistor in a ratiometric temperature measurement link, applied to the device described in claim 1, characterized in that, The method includes: Calculate the target resistance value based on the target temperature; The resistor output module is controlled to switch the corresponding resistance value. When the resistance value is switched, the temporary charge and discharge module is controlled to charge or discharge the filter capacitor. Wherein, controlling the temporary charge / discharge module to charge or discharge the filter capacitor during the resistance value switching includes: Before the resistance output module switches the resistance value, the temporary charge / discharge module is turned on; After the resistance value is switched, the temporary charging and discharging module is kept on for a first preset duration; Disconnect the temporary charge / discharge module and wait for a second preset time period to allow the voltage of the measurement node to enter the target stable range.

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