Encoder signal detection circuit and converter system

Abstract

The utility model discloses an encoder signal detection circuit and a converter system. The encoder signal detection circuit comprises a first signal input end, a second signal input end and a signal output end. The first signal input end and the second signal input end are used for accessing input signals; or, the first signal input end is used for accessing a unipolar signal, and the second signal input end is suspended; the first signal input end and the second signal input end are both connected to the input end of the filtering module, and interference of input signals of the first signal input end and the second signal input end is filtered out through the filtering module; the first resistor network comprises a first input end and a second input end, and the first input end and the second input end are connected with the signals output by the filtering module; and the first comparison module generates a first pulse signal according to the output voltage of the first resistance network. According to the invention, the adaptation degree of the encoder interface detection circuit and the encoder is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electromechanical technology, and in particular to an encoder signal detection circuit and a converter system. BACKGROUND

[0002] In a motor driving system, an encoder is used to monitor the rotating speed, position and motion state of a motor, so as to make the motor more accurate and reliable in motion and positioning control. Among them, the incremental encoder is simple and reliable to use, and is widely used in the industry. However, the electrical interface and voltage level of the incremental encoder are various, in order to solve this problem, in the related art, multiple workstations are usually reserved on the circuit, so that the adaptability of the encoder interface detection circuit and the encoder is low. CONTENT OF THE UTILITY MODEL

[0003] The present application provides an encoder signal detection circuit and a converter system to improve the adaptability of the encoder interface detection circuit and the encoder.

[0004] According to an aspect of the present application, an encoder signal detection circuit is provided, comprising a single-channel signal detection circuit, the single-channel signal detection circuit comprising: a first signal input end, a second signal input end and a signal output end; the first signal input end and the second signal input end are used to access input signals; or, the first signal input end is used to access a unipolar signal, and the second signal input end is suspended;

[0005] a filtering module, the first signal input end and the second signal input end are connected to the input end of the filtering module, and the input signals of the first signal input end and the second signal input end are filtered by the filtering module to remove interference;

[0006] a first resistance network, the first resistance network comprising a first input end and a second input end, the first input end and the second input end accessing signals output by the filtering module;

[0007] a first comparison module, the first comparison module generating a first pulse signal according to the output voltage of the first resistance network.

[0008] Optionally, the first resistance network further comprises:

[0009] The first voltage division branch, the second voltage division branch and the third voltage division branch, the first voltage division branch is connected between the first input end and the second input end of the first resistance network; the second voltage division branch is connected between the first input end and the ground end of the first resistance network, and the voltage division end of the second voltage division branch serves as the first output end of the first resistance network; the third voltage division branch is connected between the second input end and the pull-up power supply end of the first resistance network, and the voltage division end of the third voltage division branch serves as the second output end of the first resistance network.

[0010] Optionally, the number of the pull-up power supply ends electrically connected with the third voltage division branch is one.

[0011] Optionally, the first voltage division branch comprises a first resistor, a first end of the first resistor is electrically connected with the first input end of the first resistance network, and a second end of the first resistor is electrically connected with the second input end of the first resistance network.

[0012] And / or, the second voltage division branch comprises a second resistor and a third resistor, a first end of the second resistor is electrically connected with the first input end of the first resistance network, and a second end of the second resistor is electrically connected with the first output end of the first resistance network; a first end of the third resistor is electrically connected with the first output end of the first resistance network, and a second end of the third resistor is electrically connected with the ground end.

[0013] And / or, the third voltage division branch comprises a fourth resistor and a fifth resistor, a first end of the fourth resistor is electrically connected with the second input end of the first resistance network, and a second end of the fourth resistor is electrically connected with the second output end of the first resistance network; a first end of the fifth resistor is electrically connected with the second output end of the first resistance network, and a second end of the fifth resistor is electrically connected with the pull-up power supply end.

[0014] Optionally, the single-channel signal detection circuit further comprises:

[0015] A first capacitor, the first capacitor is connected between the second end of the second resistor and the ground end.

[0016] And / or, a second capacitor, the second capacitor is connected between the second end of the fourth resistor and the ground end.

[0017] Optionally, the filter module comprises a differential mode filter unit and a common mode filter unit connected in cascade.

[0018] The differential mode filter unit comprises a sixth resistor, a seventh resistor, a third capacitor and a fourth capacitor; a first end of the sixth resistor is electrically connected with the first signal input end, and a second end of the sixth resistor is electrically connected with the common mode filter unit; a first end of the third capacitor is electrically connected with the second end of the sixth resistor, and a second end of the third capacitor is electrically connected with the ground end;

[0019] a first end of the seventh resistor is electrically connected with the second signal input end, and a second end of the seventh resistor is electrically connected with the common mode filter unit; a first end of the fourth capacitor is electrically connected with the second end of the seventh resistor, and a second end of the fourth capacitor is electrically connected with the ground end.

[0020] Optionally, the encoder signal detection circuit comprises:

[0021] a first of the single-channel signal detection circuits for detecting an A-phase input signal, a second of the single-channel signal detection circuits for detecting a B-phase input signal, and a third of the single-channel signal detection circuits for detecting a Z-phase input signal.

[0022] Optionally, the single-channel signal detection circuit further comprises:

[0023] a second resistor network comprising a third input end and a fourth input end, the third input end and the fourth input end being connected to a signal output by the filter module;

[0024] the second resistor network further comprises a fourth voltage dividing branch and a fifth voltage dividing branch, the fourth voltage dividing branch being connected between the first input end of the second resistor network and the ground end, and a voltage dividing end of the fourth voltage dividing branch serving as a first output end of the second resistor network; the fifth voltage dividing branch being connected between the second input end of the second resistor network and an upper pull power supply end, and a voltage dividing end of the fifth voltage dividing branch serving as a second output end of the second resistor network;

[0025] a second comparison module for generating a second pulse signal according to voltages output by the fourth voltage dividing branch and the fifth voltage dividing branch;

[0026] wherein the input end signal of the second comparison module is connected in a manner opposite to the input end signal of the first comparison module.

[0027] Optionally, the number of the upper pull power supply ends electrically connected with the fifth voltage dividing branch is one.

[0028] Optionally, the fourth voltage dividing branch comprises an eighth resistor and a ninth resistor, a first end of the eighth resistor is electrically connected with the first input end of the second resistor network, and a second end of the eighth resistor is electrically connected with the first output end of the second resistor network; a first end of the ninth resistor is electrically connected with the first output end of the second resistor network, and a second end of the ninth resistor is electrically connected with the ground end.

[0029] And / or, the fifth voltage dividing branch comprises a tenth resistor and an eleventh resistor, a first end of the tenth resistor is electrically connected with the second input end of the second resistor network, and a second end of the tenth resistor is electrically connected with the second output end of the second resistor network; a first end of the eleventh resistor is electrically connected with the second output end of the second resistor network, and a second end of the eleventh resistor is electrically connected with the pull-up power end.

[0030] Optionally, the single-channel signal detection circuit further comprises:

[0031] a fifth capacitor connected between the second end of the eighth resistor and the ground end;

[0032] And / or, a sixth capacitor connected between the second end of the tenth resistor and the ground end.

[0033] Optionally, the encoder signal detection circuit further comprises a control module, and a signal output end of the single-channel signal detection circuit is electrically connected with the control module. According to another aspect of the present application, a converter system is provided, comprising: an encoder and the encoder signal detection circuit according to any of the embodiments of the present application; wherein the encoder is configured to detect a rotation parameter of a motor and output a signal; and the encoder signal detection circuit is configured to detect the output signal of the encoder.

[0034] The pulse signal output by the encoder signal detection circuit provided by the embodiments of the present application is only affected by the resistance in the first resistor network, and is not affected by the type and voltage level of the input signal. Therefore, the embodiments of the present application can adapt to both unipolar signal detection of the encoder at different voltage levels and bipolar signal detection of the encoder at different voltage levels, thereby improving the adaptability of the encoder interface detection circuit to the encoder.

[0035] It should be understood that the content described in this part is not intended to identify key or important features of the embodiments of the present application, nor to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0037] Figure 1 A schematic diagram of an encoder signal detection circuit provided by the related art is shown in FIG. 1.

[0038] Figure 2 A schematic diagram of an encoder signal detection circuit provided by the present application is shown in FIG. 2.

[0039] Figure 3 A schematic diagram of another encoder signal detection circuit provided by the present application is shown in FIG. 3.

[0040] Figure 4 A schematic diagram of another encoder signal detection circuit provided by the present application is shown in FIG. 4.

[0041] Figure 5 A schematic diagram of another encoder signal detection circuit provided by the present application is shown in FIG. 5.

[0042] Figure 6 A schematic diagram of another encoder signal detection circuit provided by the present application is shown in FIG. 6.

[0043] Figure 7 A schematic diagram of another encoder signal detection circuit provided by the present application is shown in FIG. 7.

[0044] Figure 8 A schematic diagram of another encoder signal detection circuit provided by the present application is shown in FIG. 8. DETAILED DESCRIPTION

[0045] In order to make the person skilled in the art better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely in the following description of the embodiments of the present application, obviously, the described embodiments are only some embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0046] It should be noted that the terms "first", "second", and the like, in the description and in the claims of the present application as well as in the above description of the figures are used to distinguish between similar objects and not necessarily for describing a specific sequential or chronological order. It is to be understood that the use of these terms in the description is not meant to limit the scope of the application to the precise embodiments described but rather a description of specific embodiments is meant to embrace all the embodiments falling within the scope of the application. Moreover, the terms "comprising", "having", "including", and the like, are meant not to be construed as being limiting but rather to be construed as meaning "comprising but not limited to". It is to be understood that the use of these terms in the description is not meant to limit the scope of the application to the precise embodiments described but rather a description of specific embodiments is meant to embrace all the embodiments falling within the scope of the application.

[0047] Figure 1 A schematic diagram of an encoder signal detection circuit provided by the related art, the encoder signal detection circuit provided by the related art comprises a plurality of signal detection circuits; each signal detection circuit comprises a first signal input end A+, a second signal input end A- and a signal output end OUT1; wherein the first signal input end A+ and the second signal input end A- are used for accessing input signals; or, the first signal input end A+ is used for accessing a unipolar signal, and the second signal input end A- is grounded; a filtering module 110, the first signal input end A+ and the second signal input end A- are both connected to the input end of the filtering module 110, and the input signals of the first signal input end A+ and the second signal input end A- are filtered by the filtering module 110 to remove interference;

[0048] The first resistance network 120 includes a first input end and a second input end, and the first input end and the second input end are connected to the signal output by the filter module 110; the first voltage division branch 121 includes: a first resistor R1, a first end of the first resistor R1 is electrically connected to the first input end of the first resistance network 120, and a second end of the first resistor R1 is electrically connected to the second input end of the first resistance network 120; and / or, the second voltage division branch 122 includes a second resistor R2 and a third resistor R3, a first end of the second resistor R2 is electrically connected to the first input end of the first resistance network 120, and a second end of the second resistor R2 is electrically connected to the first output end of the first resistance network 120; a first end of the third resistor R3 is electrically connected to the first output end of the first resistance network 120, and a second end of the third resistor R3 is electrically connected to a ground end; and / or, the third voltage division branch 123 includes a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6, a first end of the fourth resistor R4 is electrically connected to the second input end of the first resistance network 120, and a second end of the fourth resistor R4 is electrically connected to the second output end of the first resistance network 120; a first end of the fifth resistor R5 and a first end of the sixth resistor R6 are both electrically connected to the second output end of the first resistance network 120, a second end of the fifth resistor R5 is electrically connected to a pull-up power supply end VCC1, and a second end of the sixth resistor R6 is electrically connected to a pull-up power supply end VCC2. The first comparison module 130 generates a first pulse signal according to the output voltage of the first resistance network 120.

[0049] When the single-polarity signal detection of the encoder is performed, the encoder only outputs one signal, that is, an A+ signal (or an A- signal). Taking the A+ signal as an example, at this time, the A+ signal is connected to the first signal input end A+, and the voltage thereof is V1; the second signal input end A- is grounded. The A+ signal and the grounded A- signal are filtered by the filter module 110 and then output, and since the second signal input end A- is grounded, a stable reference zero voltage can be provided for the second input end of the first resistance network 120, and the voltage of the second output end of the second resistance network 120 needs to be matched with an appropriate pull-up power supply according to the voltage level, so that the adaptation degree of the encoder interface detection circuit to the encoder is low. Embodiments of the present application provide an encoder signal detection circuit, Figure 2 A circuit schematic diagram of an encoder signal detection circuit provided in an embodiment of the present application is shown in FIG. 1. Figure 2 The encoder signal detection circuit includes a single signal detection circuit, Figure 2 The single signal detection circuit is an A+ signal detection circuit, which is exemplarily shown in FIG. 1.

[0050] The single signal detection circuit includes:

[0051] The first signal input end A+, the second signal input end A- and the signal output end OUT1; the first signal input end A+ and the second signal input end A- are used for inputting signals; or, the first signal input end A+ is used for inputting a single polarity signal, and the second signal input end A- is left vacant; the filter module 110, the first signal input end A+ and the second signal input end A- are both connected to the input end of the filter module 110, and the input signals of the first signal input end A+ and the second signal input end A- are filtered by the filter module 110 to remove interference; the first resistance network 120, the first resistance network 120 includes a first input end and a second input end, and the first input end and the second input end input signals output by the filter module 110; the first comparison module 130, the first comparison module 130 generates a first pulse signal according to the output voltage of the first resistance network 120.

[0052] Exemplarily, the working principle of the single-channel signal detection circuit is as follows:

[0053] When the bipolar signal detection of the encoder is performed, that is, the first channel signal output by the encoder is input to the first signal input end A+, which is referred to as the A+ signal; the second channel signal output by the encoder is input to the second signal input end A-, which is referred to as the A- signal. After the A+ signal and the A- signal are filtered by the filter module 110, the output is obtained, the filter module 110 has little effect on the voltage of the A+ signal and the A- signal, which can be ignored, and in the subsequent calculation process, it is considered that the voltage of the A+ signal before and after filtering is unchanged, and the voltage of the A- signal before and after filtering is unchanged. The voltage of the A+ signal to the ground end is V1, and the voltage of the A- signal to the ground end is V2, then the voltage of the first input end of the first resistance network 120 is V1, and the voltage of the second input end is V2, the voltage V1 and the voltage V2 are known quantities; in addition, the voltage of the first output end of the first resistance network 120 is set as Vin1, and the voltage of the second output end is set as Vin2, the voltage Vin1 and the voltage Vin2 are input to the first comparison module 130, so that the pulse signal is output at the signal output end OUT1. Wherein, in the case that the resistance in the first resistance network 120 is determined, that is, the resistance value of the resistance in the first resistance network 120 is known, the voltage Vin1 and the voltage Vin2 are determined by the resistance in the first resistance network 120.

[0054] When the unipolar signal detection of the encoder is performed, unlike the bipolar signal detection, the encoder only outputs one signal, i.e., the A+ signal (or the A- signal). Taking the A+ signal as an example, at this time, the A+ signal is connected to the first signal input end A+, and the voltage of the A+ signal is V1; the second signal input end A- is not connected and is in a suspended state. After the A+ signal and the suspended A- signal are filtered by the filtering module 110, the voltage of the second input end of the first resistance network 120 is in an uncertain state, and the voltage Vin1 of the first output end and the voltage Vin2 of the second output end of the first resistance network 120 are still determined by the resistance in the first resistance network 120.

[0055] If the voltage input to the input end of the first comparison module 130 satisfies Vin1 > Vin2, the first comparison module 130 outputs a high level. If the voltage input to the input end of the first comparison module 130 satisfies Vin1 < Vin2, the first comparison module 130 outputs a low level. Since the voltage Vin1 and the voltage Vin2 are determined by the resistance in the first resistance network 120, the first comparison module 130 is not affected by the voltage level of the A+ signal and the A- signal when the first comparison module 130 outputs the high level and the low level (i.e., the pulse signal) during the bipolar signal detection of the encoder, and the first comparison module 130 is not affected by the voltage level of the A+ signal when the first comparison module 130 is still in the unipolar signal detection of the encoder, and is only affected by the resistance in the first resistance network 120.

[0056] In summary, the pulse signal output by the encoder signal detection circuit provided in the embodiment of the present application is only affected by the resistance in the first resistance network 120, and is not affected by the type and voltage level of the input signal. Therefore, the embodiment of the present application can adapt to the unipolar signal detection of the encoder with different voltage levels and the bipolar signal detection of the encoder with different voltage levels, thereby improving the adaptability of the encoder interface detection circuit to the encoder.

[0057] On the basis of the above-mentioned embodiment, optionally, continuing to refer to Figure 2 The first resistance network further includes: a first voltage division branch 121, a second voltage division branch 122, and a third voltage division branch 123. The first voltage division branch 121 is connected between the first input end and the second input end of the first resistance network 120. The second voltage division branch 122 is connected between the first input end of the first resistance network 120 and the ground end, and the voltage division end of the second voltage division branch 123 serves as the first output end of the first resistance network 120. The third voltage division branch 123 is connected between the second input end of the first resistance network 120 and the pull-up power supply end VCC, and the voltage division end of the third voltage division branch 123 serves as the second output end of the first resistance network 120.

[0058] When the unipolar signal detection of the encoder is performed, the voltage Vin1 is determined by the voltage V1 and the second voltage dividing branch 122. The voltage dividing ratio of the output voltage in the second voltage dividing branch 122 is determined under the condition that the resistance in the first resistance network 120 is determined, i.e. the resistance value of the resistance in the first resistance network 120 is known. Therefore, the value of the voltage Vin1 is determined. Assuming that the voltage dividing ratio of the second voltage dividing branch 122 is K1, then Vin1 = K1 x V1.

[0059] The voltage Vin2 is determined by the voltage V2, the voltage VCC of the pull-up power supply terminal and the third voltage dividing branch. The voltage dividing ratio of the output voltage in the third voltage dividing branch 123 is determined under the condition that the resistance in the first resistance network 120 is determined. Therefore, the value of the voltage Vin2 is determined. Assuming that the voltage dividing ratio of the third voltage dividing branch 123 is K2, then Vin2 = K2 x (V2 - VCC) + VCC.

[0060] Further, if the voltage input to the input terminal of the first comparison module 130 satisfies Vin1 > Vin2, i.e. Vin1 - Vin2 > 0, then the above formula Vin1 = K1 x V1 and Vin2 = K2 x (V2 - VCC) + VCC are substituted into which can be obtained: V1 - V2 > M1 x VCC; wherein M1 is determined by K1 and K2. At this time, the first comparison module 130 outputs high level.

[0061] Similarly, if the voltage input to the input terminal of the first comparison module 130 satisfies Vin1 < Vin2, then it can be obtained: V1 - V2 < M1 x VCC. At this time, the first comparison module 130 outputs low level.

[0062] From the above analysis, it can be seen that when the first comparison module 130 outputs high level and low level (i.e. pulse signal), it is not affected by the voltage level of the A+ signal and the A- signal. No matter under which voltage level, as long as the voltage of the A+ signal and the A- signal can satisfy V1 - V2 > M1 x VCC, the single signal detection circuit outputs high level; as long as the voltage of the A+ signal and the A- signal can satisfy V1 - V2 < M1 x VCC, the single signal detection circuit outputs low level.

[0063] When the unipolar signal detection of the encoder is performed, the voltage Vin1 is still determined by the voltage V1 and the second voltage dividing branch 122. The voltage Vin1 is the same as when the bipolar signal detection is performed, i.e. Vin1 = K1 x V1.

[0064] The voltage Vin2 is determined by the voltage V1, the first voltage dividing branch 121, the voltage VCC of the pull-up power supply end and the third voltage dividing branch. The resistance value of the first voltage dividing branch 121 is determined in the case that the resistances in the first resistance network 120 are determined, the voltage dividing ratio of the output voltage in the third voltage dividing branch 122 is determined, and thus the value of the voltage Vin2 is determined. The voltage dividing ratio of the voltage output by the voltage dividing branch composed of the first voltage dividing branch 121 and the third voltage dividing branch 123 is determined and set as K3, and thus Vin2 = K3 x (V1-VCC) + VCC.

[0065] Further, if the voltage input to the input end of the first comparison module 130 satisfies Vin1 > Vin2, i.e., Vin1-Vin2 > 0, the above formula Vin1 = K1 x V1 and Vin2 = K3 x (V1-VCC) + VCC are substituted into which can be obtained: V1 > M2 x VCC; wherein M2 is determined by K1 and K3. At this time, the first comparison module 130 outputs a high level.

[0066] Similarly, if the voltage input to the input end of the first comparison module 130 satisfies Vin1 < Vin2, it can be obtained: V1 < M2 x VCC. At this time, the first comparison module 130 outputs a low level.

[0067] From the above analysis, it can be seen that when the first comparison module 130 outputs a high level and a low level (i.e., a pulse signal), it is not affected by the voltage level of the A+ signal. No matter under which voltage level, as long as the voltage of the A+ signal can satisfy V1 > M2 x VCC, the single-channel signal detection circuit outputs a high level; as long as the voltage of the A+ signal can satisfy V1 < M2 x VCC, the single-channel signal detection circuit outputs a low level.

[0068] The technical principle of the encoder only outputting the A- signal is similar to the technical principle of the encoder only outputting the A+ signal, and thus is not described again.

[0069] On the basis of the above embodiments, optionally, the number of pull-up power supply ends to which the third voltage dividing branch is electrically connected is one.

[0070] In the case of resistance determination in the first resistance network 120, during unipolar signal detection, no matter at which voltage level, as long as the voltage of the A+ signal and the A- signal can satisfy V1-V2>M1xVCC, the single-channel signal detection circuit outputs high level; as long as the voltage of the A+ signal and the A- signal can satisfy V1-V2M1xVCC, the single-channel signal detection circuit outputs low level; during unipolar signal detection, no matter at which voltage level, as long as the voltage of the A+ signal can satisfy V1>M2xVCC, the single-channel signal detection circuit outputs high level; as long as the voltage of the A+ signal can satisfy V1M2xVCC, the single-channel signal detection circuit outputs low level. Obviously, the number of the pull-up power supply end electrically connected to the third voltage division branch can meet the requirement.

[0071] On the basis of the above-mentioned embodiments, optionally, there are multiple ways of setting the first voltage division branch 121, the second voltage division branch 122 and the third voltage division branch 123, which will be specifically described below, but not as a limitation to the present application.

[0072] Figure 3 Another circuit schematic diagram of an encoder signal detection circuit provided by the embodiments of the present application is shown in FIG. 4. Figure 3 In an embodiment, optionally, the first voltage division branch 121 comprises a first resistor R1, a first end of the first resistor R1 is electrically connected to the first input end of the first resistance network 120, and a second end of the first resistor R1 is electrically connected to the second input end of the first resistance network 120. The first resistor R1 is arranged in the first voltage division branch 121 in the embodiments of the present application, which is combined with the resistors in the second voltage division branch 122 and the third voltage division branch 123 to realize the voltage division function. In this way, the circuit structure is simple and easy to implement.

[0073] It should be noted that in actual application, the number of resistors in the first voltage division branch 121 can be adjusted as needed, and when two or more resistors are arranged in the first voltage division branch 121, these resistors can be connected in series or in parallel.

[0074] Continuing to refer to FIG. 4, Figure 3In an embodiment, optionally, the second voltage dividing branch 122 includes a second resistor R2 and a third resistor R3, a first end of the second resistor R2 is electrically connected with the first input end of the first resistor network 120, and a second end of the second resistor R2 is electrically connected with the first output end of the first resistor network 120; a first end of the third resistor R3 is electrically connected with the first output end of the first resistor network 120, and a second end of the third resistor R3 is electrically connected with the ground end. In the second voltage dividing branch 122, the second resistor R2 and the third resistor R3 are arranged, wherein a connection node of the second resistor R2 and the third resistor R3 is a voltage dividing node of the second voltage dividing branch 122, so as to achieve voltage division of the voltage at the first input end of the first resistor network 120; or, in combination with the first voltage dividing branch 121, voltage division of the voltage at the second input end of the first resistor network 120 when the voltage at the first input end of the first resistor network 120 is in a voltage uncertain state. In this way, the circuit structure is simple and easy to implement.

[0075] It should be noted that in actual application, the number of resistors in the second voltage dividing branch 122 can be adjusted as needed. Specifically, the second resistor R2 can also be equivalent to two or more resistors, and these resistors can be connected in series or in parallel; and the third resistor R3 can also be equivalent to two or more resistors, and these resistors can be connected in series or in parallel.

[0076] Continuing to refer to Figure 3 In an embodiment, optionally, the third voltage dividing branch 123 includes a fourth resistor R4 and a fifth resistor R5, a first end of the fourth resistor R4 is electrically connected with the second input end of the first resistor network 120, and a second end of the fourth resistor R4 is electrically connected with the second output end of the first resistor network 120; a first end of the fifth resistor R5 is electrically connected with the second output end of the first resistor network 120, and a second end of the fifth resistor R5 is electrically connected with the pull-up power supply end. In the third voltage dividing branch 123, the fourth resistor R4 and the fifth resistor R5 are arranged, wherein a connection node of the fourth resistor R4 and the fifth resistor R5 is a voltage dividing node of the third voltage dividing branch 123, so as to achieve voltage division of the voltage at the second input end of the first resistor network 120; or, in combination with the first voltage dividing branch 121, voltage division of the voltage at the first input end of the first resistor network 120 when the voltage at the second input end of the first resistor network 120 is in a voltage uncertain state. In this way, the circuit structure is simple and easy to implement.

[0077] It should be noted that in practical applications, the number of resistors in the third voltage divider branch 123 can be adjusted as needed. Specifically, the fourth resistor R4 can also be equivalent to two or more resistors, which can be connected in series and parallel; and the fifth resistor R5 can also be equivalent to two or more resistors, which can be connected in series and parallel.

[0078] exist Figure 3 In the illustrated embodiment, if the resistance values ​​of each resistor in the first resistor network 120 are determined, that is, after the resistances in the first resistor network 120 are determined, the specific values ​​of coefficients K1, K2, M1 and M2 can be determined, which will be explained in detail below.

[0079] Optionally, R2 = R4, R3 = R5 = R1 are set. When performing bipolar signal detection of the encoder, Formula 1 can be obtained by calculating the second voltage divider branch 122:

[0080]

[0081] Therefore,

[0082] Formula 2 can be derived from the calculation of the third voltage-dividing branch 123:

[0083]

[0084] Therefore,

[0085] If the voltage input to the input terminal of the first comparison module 130 satisfies Vin1 > Vin2, i.e., Vin1 - Vin2 > 0, then substituting into formulas 1 and 2, R2 = R4 and R3 = R5 = R1, we can obtain the formula...

[0086] Formula 3:

[0087]

[0088] Therefore,

[0089] Similarly, if the voltage input to the input terminal of the first comparison module 130 satisfies Vin1 < Vin2, then Formula 4 can be derived:

[0090]

[0091] From the above analysis, the first comparison module 130 output high and low (i.e. pulse signal) level, not affected by the voltage level of A+ signal and A- signal. No matter in which voltage level, as long as the voltage of A+ signal and A- signal can satisfy V1-V2>M1xVCC, wherein M1 is the ratio of the second resistor R2 and the third resistor R3, the single signal detection circuit output high level; as long as the voltage of A+ signal and A- signal can satisfy V1-V2M1xVCC, the single signal detection circuit output low level.

[0092] When the single polarity signal detection of the encoder is performed, and the encoder only outputs A+ signal, the above formula 1 can be obtained by calculating the second voltage division branch 122.

[0093] The formula 5 can be obtained by calculating the first voltage division branch 121 and the third voltage division branch 123:

[0094]

[0095] Therefore, it can be seen that,

[0096] If the voltage input to the input end of the first comparison module 130 satisfies Vin1> Vin2, i.e. Vin1-Vin2> 0, then by substituting formula 1, formula 5, R2=R4 and R3=R5=R1, it can be obtained that

[0097] Formula 6:

[0098]

[0099] Therefore, it can be seen that,

[0100] Similarly, if the voltage input to the input end of the first comparison module 130 satisfies Vin1< Vin2, formula 7 can be obtained:

[0101]

[0102] From the above analysis, the first comparison module 130 output high and low (i.e. pulse signal) level, not affected by the voltage level of A+ signal. No matter in which voltage level, as long as the voltage of A+ signal can satisfy V1>M2xVCC, wherein M2 is the ratio of the second resistor R2 and the third resistor R3, The single signal detection circuit output high level; as long as the voltage of A+ signal can satisfy V1M2xVCC, the single signal detection circuit output low level.

[0103] On the basis of the above-mentioned embodiments, optionally, the single-channel signal detection circuit further comprises a first capacitor and / or a second capacitor, the first capacitor and the resistance in the second voltage dividing branch constitute a low-pass filter, the second capacitor and the resistance in the third voltage dividing branch constitute a low-pass filter, and the signal is filtered again, which is beneficial to the stability of signal detection.

[0104] Figure 4 Another circuit schematic diagram of an encoder signal detection circuit is provided in the embodiments of the present application. Referring to Figure 4 , for example, the single-channel signal detection circuit further comprises a first capacitor C1 and a second capacitor C2. The first capacitor C1 is connected between the second end of the second resistor R2 and the ground end, and the second capacitor C2 is connected between the second end of the fourth resistor R4 and the ground end. The first capacitor C1 and the second resistor R2 constitute a low-pass filter for filtering the voltage Vin1, and the second capacitor C2 and the fourth resistor R4 constitute a low-pass filter for filtering the voltage Vin2.

[0105] Figure 5 Another circuit schematic diagram of an encoder signal detection circuit is provided in the embodiments of the present application. Referring to Figure 5 On the basis of the above-mentioned embodiments, optionally, the filtering module 110 comprises a differential mode filter unit 111 and a common mode filter unit 112 connected in cascade.

[0106] The differential mode filter unit 111 comprises a sixth resistor R6, a seventh resistor R7, a third capacitor C3 and a fourth capacitor C4. The first end of the sixth resistor R6 is electrically connected with the first signal input end A+, and the second end of the sixth resistor R6 is electrically connected with the common mode filter unit 112. The first end of the third capacitor C3 is electrically connected with the second end of the sixth resistor R6, and the second end of the third capacitor C3 is electrically connected with the ground end.

[0107] The first end of the seventh resistor R7 is electrically connected with the second signal input end A-, and the second end of the seventh resistor R7 is electrically connected with the common mode filter unit 112. The first end of the fourth capacitor C4 is electrically connected with the second end of the seventh resistor R7, and the second end of the fourth capacitor C4 is electrically connected with the ground end.

[0108] In the filtering module 110, the differential mode filter unit 111 and the common mode filter unit 112 are arranged in the embodiments of the present application, which can effectively filter out the common mode and differential mode interference in the encoder signal. In addition, the differential mode filter unit 111 comprises the sixth resistor R6, the seventh resistor R7, the third capacitor C3 and the fourth capacitor C4, which has a simple structure and is easy to implement. The resistance values of the sixth resistor R6 and the seventh resistor R7 can be set to be relatively small, which is beneficial to reducing the influence of the differential mode filter unit 111 on the resistance voltage division calculation of the subsequent circuit.

[0109] On the basis of the above embodiments, optionally, the common-mode filter unit 112 comprises a common-mode inductor to filter out the common-mode interference existing in the line, and two coils in the common-mode inductor are connected to the signal A+ and the signal A- respectively. In this way, the circuit structure is simple and easy to implement.

[0110] On the basis of the above embodiments, optionally, the first comparison module 130 comprises a comparator, and two input ends of the comparator are connected to the voltage Vin1 and the voltage Vin2 respectively. In this way, the circuit structure is simple and easy to implement.

[0111] Figure 6 Another circuit schematic diagram of an encoder signal detection circuit provided by the embodiments of the present application is provided. Referring to Figure 6 On the basis of the above embodiments, optionally, the embodiments of the present application can be applied to an ABZ three-way encoder. Specifically, the encoder signal detection circuit comprises: a first single-channel signal detection circuit 100 for detecting an A-phase input signal, a second single-channel signal detection circuit 200 for detecting a B-phase input signal, and a third single-channel signal detection circuit 300 for detecting a Z-phase input signal. The signal output ends of the first single-channel signal detection circuit 100, the second single-channel signal detection circuit 200, and the third single-channel signal detection circuit 300 are OUT1, OUT2, and OUT3 respectively, and the circuit structures of the three single-channel signal detection circuits and the selected types of the devices are all the same, and the resistors in the first resistor network 120 can be the same.

[0112] In summary, the pulse signals output by the single-channel signal detection circuits of the encoder signal detection circuit provided by the embodiments of the present application are not affected by the type and voltage level of the input signals. Specifically, without modifying the resistors in the first resistor network 120, the encoder signal detection circuit can adapt to both unipolar signal detection of the encoder, for example, can support HTL (High Threshold Logic) level signals, and bipolar signal detection of the encoder, for example, can support TTL (Transistor-Transistor Logic) level signals and HTL level signals, and can adapt to different voltage levels. Therefore, the embodiments of the present application improve the adaptation complexity of the encoder interface detection circuit and the encoder. In addition, when bipolar signal detection is performed, the pulse signals output by the encoder signal detection circuit are related to the difference between the two input signals, and the anti-interference ability is strong, which is conducive to coping with the complex electromagnetic environment on site.

[0113] On the basis of the above embodiments, the embodiments of the present application further provide an encoder signal detection circuit capable of detecting broken wires or misaligned wires, which will be described in detail below.

[0114] Figure 7Another circuit schematic of an encoder signal detection circuit provided by an embodiment of the present application. Referring to Figure 7 In an embodiment, optionally, the single-path signal detection circuit further comprises:

[0115] A second resistance network 140, the second resistance network 140 comprises a third input end and a fourth input end, the third input end and the fourth input end are connected to the signal output by the filter module 110;

[0116] The second resistance network 140 further comprises a fourth voltage dividing branch 141 and a fifth voltage dividing branch 151, the fourth voltage dividing branch 141 is connected between the first input end and the ground end of the second resistance network 140, and the voltage dividing end of the fourth voltage dividing branch 141 is used as the third output end of the second resistance network 140; the fifth voltage dividing branch 151 is connected between the second input end and the pull-up power supply end of the second resistance network 140, and the voltage dividing end of the fifth voltage dividing branch 151 is used as the second output end of the second resistance network 140;

[0117] A second comparison module 150, the second comparison module 150 generates a second pulse signal according to the voltages output by the fourth voltage dividing branch 141 and the fifth voltage dividing branch 151; wherein the connection mode of the input end signal of the second comparison module 150 is opposite to that of the first comparison module 130.

[0118] Specifically, the setting mode of the second resistance network 140 is similar to that of the first resistance network 120, and the first voltage dividing branch 121 in the first resistance network 120 can also be multiplexed by the second resistance network 140. Therefore, the voltage dividing principle of the second resistance network 140 and the calculation method of the output voltage are the same as those of the first resistance network 140. In the case of setting the voltage dividing ratio of the second resistance network 140 in analogy with the first resistance network 120, the voltage of the third output end of the second resistance network 140 is the same as that of the first output end of the first resistance network 120, and the voltage of the fourth output end of the second resistance network 140 is the same as that of the second output end of the first resistance network 120.

[0119] The connection mode of the input signal of the second comparison module 150 with the input signal of the first comparison module 130 is opposite, that is, if the non-inverting input terminal + of the first comparison module 130 is electrically connected with the first output terminal of the first resistance network 120, and the inverting input terminal - is electrically connected with the second output terminal of the first resistance network 120; then the non-inverting input terminal + of the second comparison module 150 is electrically connected with the fourth output terminal of the second resistance network 140, and the inverting input terminal - is electrically connected with the third output terminal of the second resistance network 140. In another embodiment, if the inverting input terminal - of the first comparison module 130 is electrically connected with the first output terminal of the first resistance network 120, and the non-inverting input terminal + is electrically connected with the second output terminal of the first resistance network 120; then the inverting input terminal - of the second comparison module 150 is electrically connected with the fourth output terminal of the second resistance network 140, and the non-inverting input terminal + is electrically connected with the third output terminal of the second resistance network 140.

[0120] In this way, the A+ signal and the A- signal enter the two comparison modules of opposite polarities, that is, the first comparison module 130 and the second comparison module 150, through the same resistance network, and the generated pulse signals are complementary pulse signals. If there is a signal generation disconnection or misconnection, the signals generated by the first comparison module 130 and the second comparison module 150 are not complementary pulse signals, that is, the encoder disconnection or misconnection fault can be judged. The embodiment of the application can not only detect disconnection or misconnection in the running state of the encoder, but also detect disconnection or misconnection in the stopped state of the encoder. Because, even if the encoder is not running, as long as the encoder generates a signal after being powered on, according to the running principle of the embodiment of the application, as long as the encoder signal detection circuit receives a signal that is not a differential signal, the disconnection or misconnection of the encoder can be judged. Therefore, the embodiment of the application can detect whether all the signal lines of the encoder are normally connected. In summary, the embodiment of the application is not limited to the disconnection fault condition that can only occur in the running state of the encoder, and has a wider application range and more powerful functions.

[0121] It should be noted that in the above embodiment, the second resistance network 140 and the first resistance network 120 share the first voltage division branch 121 and the filter module 110; in another embodiment, a sixth voltage division branch corresponding to the first voltage division branch 121 can be independently provided in the second resistance network 140; in another embodiment, a filter module can be additionally provided for filtering the input signal of the second resistance network 140. Figure 7 In the embodiment shown, the second resistance network 140 and the first resistance network 120 share the first voltage division branch 121 and the filter module 110, which can ensure the stability of the output signal and reduce the number of devices, thereby simplifying the resistance in the first resistance network 120.

[0122] With reference to Figure 7 On the basis of the above embodiments, optionally, the number of pull-up power supply ends electrically connected to the fifth voltage division branch is one. The fourth voltage division branch 141 comprises an eighth resistor R8 and a ninth resistor R9. The first end of the eighth resistor R8 is electrically connected to the first input end of the second resistor network 140, and the second end of the eighth resistor R8 is electrically connected to the third output end of the second resistor network 140. The first end of the ninth resistor R9 is electrically connected to the third output end of the second resistor network 140, and the second end of the ninth resistor R9 is electrically connected to the ground end.

[0123] The fifth voltage division branch 151 comprises a tenth resistor R10 and an eleventh resistor R11. The first end of the tenth resistor R10 is electrically connected to the second input end of the second resistor network 140, and the second end of the tenth resistor R10 is electrically connected to the second output end of the first resistor network 120. The first end of the eleventh resistor R11 is electrically connected to the fourth output end of the second resistor network 140, and the second end of the eleventh resistor R11 is electrically connected to the pull-up power supply end.

[0124] The embodiments of the present application are thus configured so that the circuit structure of the fourth voltage division branch 141 is the same as that of the second voltage division branch 122, and the circuit structure of the fifth voltage division branch 151 is the same as that of the third voltage division branch 123, which is conducive to the second resistor network 140 and the first resistor network 120 outputting the same signal.

[0125] With reference to Figure 7 On the basis of the above embodiments, optionally, the single-channel signal detection circuit further comprises a fifth capacitor C5 and a sixth capacitor C6. The fifth capacitor C5 is connected between the second end of the eighth resistor R8 and the ground end, and the sixth capacitor C6 is connected between the second end of the tenth resistor R10 and the ground end. The fifth capacitor C5 and the eighth resistor R8 constitute a low-pass filter for filtering the voltage Vin1, and the sixth capacitor C6 and the tenth resistor R10 constitute a low-pass filter for filtering the voltage Vin2. Such a configuration is conducive to the signals received by the first comparison module 130 and the second comparison module 150 being signals of completely opposite polarities.

[0126] Figure 8 Another circuit schematic diagram of an encoder signal detection circuit provided by the embodiments of the present application is provided. With reference to Figure 8On the basis of the above-mentioned embodiments, the encoder signal detection circuit further comprises a control module 400, and the signal output end OUT1 of the single-channel signal detection circuit is electrically connected to the control module 400. For example, when applied to an ABZ three-channel encoder, the signal output ends OUT1 of the three single-channel signal detection circuits are all connected to the control module 400, and the control module 400 is used to monitor the rotating speed, position and motion state of the motor. When the encoder signal detection circuit capable of detecting line breakage or line misconnection is used, the output ends of the first comparison module 130 and the second comparison module 150 are both connected to the control module 400, and the control module 400 is used to determine whether the signal is disconnected or misconnected.

[0127] The application further provides a converter system. The converter system comprises an encoder and an encoder signal detection circuit as provided in any of the embodiments of the application, wherein the encoder is used to detect the rotating parameter of the motor and output a signal, and the encoder signal detection circuit is used to detect the output signal of the encoder. Since the converter system comprises the encoder signal detection circuit as provided in any of the embodiments of the application, the technical principles and effects are similar, and thus will not be repeated.

[0128] It should be understood that the steps shown in the above-mentioned various forms of flowcharts can be reordered, added or deleted. For example, the steps described in the application can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions of the application can be achieved, and the present application is not limited in this regard.

[0129] The above-mentioned specific embodiments do not constitute a limitation on the protection scope of the application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements and improvements made within the spirit and principles of the application should be included in the protection scope of the application.

Claims

1. An encoder signal detection circuit, characterized by The single-channel signal detection circuit comprises a first signal input end, a second signal input end and a signal output end; the first signal input end and the second signal input end are used for accessing input signals; or the first signal input end is used for accessing a single-polarity signal, and the second signal input end is left unconnected; a filtering module, the first signal input end and the second signal input end are connected to the input end of the filtering module, and the input signals of the first signal input end and the second signal input end are filtered by the filtering module to remove interference; a first resistance network, the first resistance network comprises a first input end and a second input end, and the first input end and the second input end access signals output by the filtering module; a first comparison module, the first comparison module generates a first pulse signal according to the output voltage of the first resistance network.

2. The encoder signal detection circuit of claim 1, wherein, The first resistance network further comprises: a first voltage division branch, a second voltage division branch and a third voltage division branch, the first voltage division branch is connected between the first input end and the second input end of the first resistance network; the second voltage division branch is connected between the first input end of the first resistance network and a ground end, and the voltage division end of the second voltage division branch serves as the first output end of the first resistance network; the third voltage division branch is connected between the second input end of the first resistance network and a pull-up power supply end, and the voltage division end of the third voltage division branch serves as the second output end of the first resistance network.

3. The encoder signal detection circuit of claim 2, wherein, The number of the pull-up power supply ends electrically connected with the third voltage division branch is one.

4. The encoder signal detection circuit according to claim 2, characterized in that the first voltage division branch comprises a first resistor, a first end of the first resistor is electrically connected with the first input end of the first resistance network, and a second end of the first resistor is electrically connected with the second input end of the first resistance network; and / or, the second voltage division branch comprises a second resistor and a third resistor, a first end of the second resistor is electrically connected with the first input end of the first resistance network, and a second end of the second resistor is electrically connected with the first output end of the first resistance network; a first end of the third resistor is electrically connected with the first output end of the first resistance network, and a second end of the third resistor is electrically connected with the ground end; and / or, the third voltage division branch comprises a fourth resistor and a fifth resistor, a first end of the fourth resistor is electrically connected with the second input end of the first resistance network, and a second end of the fourth resistor is electrically connected with the second output end of the first resistance network; a first end of the fifth resistor is electrically connected with the second output end of the first resistance network, and a second end of the fifth resistor is electrically connected with the pull-up power supply end.

5. The encoder signal detection circuit of claim 4, wherein, The single-channel signal detection circuit further comprises: a first capacitor, the first capacitor is connected between the second end of the second resistor and the ground end; and / or, a second capacitor, the second capacitor is connected between the second end of the fourth resistor and the ground end.

6. The encoder signal detection circuit of claim 1, wherein, The filtering module comprises a differential mode filtering unit and a common mode filtering unit connected in cascade; The differential mode filter unit comprises a sixth resistor, a seventh resistor, a third capacitor and a fourth capacitor; a first end of the sixth resistor is electrically connected with the first signal input end, and a second end of the sixth resistor is electrically connected with the common mode filter unit; a first end of the third capacitor is electrically connected with the second end of the sixth resistor, and a second end of the third capacitor is electrically connected with the ground end; a first end of the seventh resistor is electrically connected with the second signal input end, and a second end of the seventh resistor is electrically connected with the common mode filter unit; a first end of the fourth capacitor is electrically connected with the second end of the seventh resistor, and a second end of the fourth capacitor is electrically connected with the ground end.

7. The encoder signal detection circuit of claim 1, wherein, The encoder signal detection circuit comprises: a first single-channel signal detection circuit for detecting an A-phase input signal, a second single-channel signal detection circuit for detecting a B-phase input signal and a third single-channel signal detection circuit for detecting a Z-phase input signal.

8. The encoder signal detection circuit according to any one of claims 1 to 7, characterized in that The single-channel signal detection circuit further comprises: a second resistor network comprising a third input end and a fourth input end, the third input end and the fourth input end being connected to signals output by the filter module; the second resistor network further comprises a fourth voltage dividing branch and a fifth voltage dividing branch, the fourth voltage dividing branch being connected between the first input end of the second resistor network and the ground end, and a voltage dividing end of the fourth voltage dividing branch serving as a first output end of the second resistor network; the fifth voltage dividing branch being connected between the second input end of the second resistor network and a pull-up power supply end, and a voltage dividing end of the fifth voltage dividing branch serving as a second output end of the second resistor network; a second comparison module for generating a second pulse signal according to voltages output by the fourth voltage dividing branch and the fifth voltage dividing branch; wherein the input end signal of the second comparison module is connected in a manner opposite to the input end signal of the first comparison module.

9. The encoder signal detection circuit of claim 8, wherein, The number of pull-up power supply ends electrically connected with the fifth voltage dividing branch is one.

10. The encoder signal detection circuit according to claim 8, wherein the fourth voltage dividing branch comprises an eighth resistor and a ninth resistor, a first end of the eighth resistor being electrically connected with the first input end of the second resistor network, and a second end of the eighth resistor being electrically connected with the first output end of the second resistor network; a first end of the ninth resistor being electrically connected with the first output end of the second resistor network, and a second end of the ninth resistor being electrically connected with the ground end; and / or, the fifth voltage dividing branch comprises a tenth resistor and an eleventh resistor, a first end of the tenth resistor being electrically connected with the second input end of the second resistor network, and a second end of the tenth resistor being electrically connected with the second output end of the second resistor network; a first end of the eleventh resistor being electrically connected with the second output end of the second resistor network, and a second end of the eleventh resistor being electrically connected with the pull-up power supply end.

11. The encoder signal detection circuit of claim 10, wherein, The single-channel signal detection circuit further comprises: a fifth capacitor connected between the second end of the eighth resistor and the ground end; And / or a sixth capacitor connected between the second end of the tenth resistor and the ground terminal.

12. The encoder signal detection circuit of claim 1, wherein, The control module is electrically connected with the signal output terminal of the single-channel signal detection circuit.

13. A converter system characterized by Comprise: An encoder and the encoder signal detection circuit according to any one of claims 1-12; wherein the encoder is used for detecting the rotating parameter of the motor and outputting a signal; and the encoder signal detection circuit is used for detecting the output signal of the encoder.

Images