CN220104335U

CN220104335U - Torque signal acquisition circuit, sensing device and robot thereof

Info

Publication number: CN220104335U
Application number: CN202320726178.9U
Authority: CN
Inventors: 张海滨; 何文锋; 许晋诚
Original assignee: Passini Perception Technology Shenzhen Co ltd
Current assignee: Passini Perception Technology Shenzhen Co ltd
Priority date: 2023-03-25
Filing date: 2023-03-25
Publication date: 2023-11-28
Anticipated expiration: 2033-03-25

Abstract

The embodiment of the utility model belongs to the technical field of sensors, and relates to a signal acquisition circuit of torque, which comprises: the full-bridge strain circuit, the amplifying circuit, the filter, the analog-to-digital converter and the power supply conversion module; the power conversion module includes: a first voltage stabilizing unit and a second voltage stabilizing unit; the output end of the full-bridge strain circuit is connected with the input end of the amplifying circuit; the output end of the amplifying circuit is connected with the input end of the filter; the output end of the filter is connected with the input end of the analog-to-digital converter; the output end of the first voltage stabilizing unit is connected with the voltage input end of the full-bridge strain circuit; the output end of the second voltage stabilizing unit is connected with the voltage input end of the amplifying circuit. The utility model also relates to a sensing device/robot. The technical scheme provided by the utility model can improve the measurement precision of the collected weak signals and ensure the reliability of the performance.

Description

Torque signal acquisition circuit, sensing device and robot thereof

Technical Field

The utility model relates to the technical field of robots, in particular to a signal acquisition circuit and a sensing device of torque and a robot thereof.

Background

The joint force sensor is one of the hardware foundation and the core of the flexible robot, and most of the sensing devices of the current mainstream force sensor adopt strain gages or Hall sensors, and the principle is that when the force sensor is acted by external torque, the mechanical structure can be slightly changed, so that the resistance value or voltage of the sensing device is slightly changed. Accurate acquisition of this weak signal has therefore been a difficulty and pain point affecting the performance of the force sensor.

Disclosure of Invention

Based on the above, the embodiment of the utility model provides a signal acquisition circuit, a sensing device and a robot thereof for torque, so as to improve the measurement precision of the acquired weak signals and ensure the reliability of circuit performance.

In a first aspect, an embodiment of the present utility model provides a signal acquisition circuit for torque, which specifically includes the following technical scheme:

a signal acquisition circuit of moment of torsion for carry out signal acquisition to the joint moment of torsion of robot, include: the full-bridge strain circuit, the amplifying circuit, the filter, the analog-to-digital converter and the power supply conversion module; the power conversion module includes: a first voltage stabilizing unit and a second voltage stabilizing unit;

the output end of the full-bridge strain circuit is connected with the input end of the amplifying circuit;

the output end of the amplifying circuit is connected with the input end of the filter;

the output end of the filter is connected with the input end of the analog-to-digital converter;

the output end of the first voltage stabilizing unit is connected with the voltage input end of the full-bridge strain circuit and is used for providing first voltage stabilization for the full-bridge strain circuit;

the output end of the second voltage stabilizing unit is connected with the voltage input end of the amplifying circuit and used for providing second voltage stabilizing for the amplifying circuit.

Further, the power conversion module further comprises a boosting unit;

the output end of the boosting unit is connected with the input end of the first voltage stabilizing unit so as to stabilize the voltage input into the boosting unit through the first voltage stabilizing unit after boosting the voltage through the boosting unit.

Further, the boosting unit includes an LT1054 boosting chip.

Further, the boosting unit includes: the basic voltage inversion module and the voltage inverse multiplication module;

the basic voltage inversion module inverts and boosts the voltage input into the basic voltage inversion module, and then sends the voltage to the voltage inverse multiplication module, and the voltage inverse multiplication module performs inverse multiplication and boosting.

Further, the first voltage stabilizing unit includes: a high-precision voltage stabilizing chip; and/or

The first voltage stabilizing unit includes: the device comprises a current limiting resistor, a first voltage stabilizing chip, a first resistor and a second resistor;

the cathode of the voltage stabilizing chip is connected in series with the current limiting resistor so as to limit the current through the current limiting resistor; the anode is grounded; the reference electrode is respectively connected with one end of the first resistor and one end of the second resistor;

the other end of the second resistor is grounded; the other end of the first resistor is connected with the cathode of the voltage stabilizing chip.

Further, the boosting unit boosts the voltage to 30V; the first voltage stabilizing unit is used for stabilizing the voltage to 25V.

Further, the second voltage stabilizing unit comprises an adjustable voltage reference chip; and/or

The second voltage stabilizing unit includes: the second voltage stabilizing chip and the voltage dividing circuit;

the voltage dividing circuit is connected with the second voltage stabilizing chip, so that the second voltage stabilizing chip outputs the bias voltage required by the amplifying circuit based on the input voltage of the second voltage stabilizing unit.

Further, the full-bridge strain circuit comprises four bridge arms; each bridge arm is connected with a strain gauge; or (b)

The full-bridge strain circuit comprises four bridge arms; each bridge arm is connected with two strain gauges; the resistance values of the strain gauges of each bridge arm and two adjacent bridge arms are in the same direction, and the resistance values of the strain gauges of the opposite bridge arms are in the same direction.

In a second aspect, embodiments of the present utility model provide a sensing device comprising a strain gauge and a signal acquisition circuit for torque as described in any of the above.

In a third aspect, embodiments of the present utility model provide a robot comprising a sensing device as described above.

Compared with the prior art, the embodiment of the utility model has the following main beneficial effects:

the embodiment of the utility model reads the weak voltage electric signal corresponding to the strain resistance change by adopting the full-bridge strain circuit; amplifying the weak voltage signal through an amplifying circuit; filtering the amplified voltage signal through a filter; and the voltage analog signal is converted into a digital signal through the ADC module, so that the measurement accuracy of the collected weak signal is improved, and the reliability of the circuit performance is ensured.

In addition, the first voltage stabilizing unit is arranged to ensure that the power supply provided for the full-bridge strain circuit is not influenced by external interference, so that the acquisition accuracy of the signal acquisition circuit is improved.

Drawings

In order to more clearly illustrate the utility model or the solutions of the prior art, a brief description will be given below of the drawings used in the description of the embodiments or the prior art, it being obvious that the drawings in the description below are some embodiments of the utility model and that other drawings can be obtained from them without the inventive effort of a person skilled in the art.

FIG. 1 is a schematic diagram of a frame structure of one embodiment of a torque signal acquisition circuit provided by the present utility model;

FIG. 2 is a schematic diagram of a frame structure of another embodiment of a torque signal acquisition circuit provided by the present utility model;

FIG. 3 is a circuit diagram of one embodiment of a first voltage regulator unit provided by the present utility model;

FIG. 4 is a circuit diagram of one embodiment of a second voltage regulator unit and amplifier provided by the present utility model;

FIG. 5 is a circuit diagram of one embodiment of a boost unit provided by the present utility model;

FIG. 6A is a schematic structural view of one embodiment of a four strain gage arrangement provided by the present utility model;

FIG. 6B is a schematic diagram of a frame structure of one embodiment of a full-bridge strain circuit corresponding to the strain gauge arrangement of FIG. 6A in accordance with the present utility model;

FIG. 7A is a schematic illustration of the structure of one embodiment of an eight strain gage arrangement provided by the present utility model;

FIG. 7B is a schematic diagram of a frame structure of one embodiment of a full bridge strain circuit corresponding to the strain gauge arrangement of FIG. 7A in accordance with the present utility model.

Detailed Description

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs; the terminology used in the description of the applications herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model; the terms "comprising" and "having" and any variations thereof in the description of the utility model and the claims and the description of the drawings above are intended to cover a non-exclusive inclusion. The terms first, second and the like in the description and in the claims or in the above-described figures, are used for distinguishing between different objects and not necessarily for describing a sequential or chronological order.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the utility model. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

In order to make the person skilled in the art better understand the solution of the present utility model, the technical solution of the embodiment of the present utility model will be clearly and completely described below with reference to the accompanying drawings.

As shown in fig. 1, fig. 1 is a schematic diagram of a frame structure of an embodiment of a torque signal acquisition circuit provided by the present utility model.

The embodiment of the utility model provides a signal acquisition circuit of torque, the circuit 10 includes: a full-bridge strain circuit 11, an amplifying circuit 12, a filter 13, an analog-to-digital converter (ADC) 14 and a power conversion module 15; the power conversion module 15 includes: a first voltage stabilizing unit 151 and a second voltage stabilizing unit 152.

The full-bridge strain circuit 11 is used for collecting voltage signals after the strain gauge is stressed.

In general, since an elastic beam of a torque sensor attached to a joint is deformed when it is twisted, a strain gauge needs to be attached to a sensitive position of the elastic beam, and a sensitive material of the strain gauge is generally a metal filament, and a resistance value of the strain gauge is slightly changed under a stress condition. The full-bridge strain circuit 11 generally comprises four bridge arms, and strain gauges are connected into the bridge arms according to requirements, so that corresponding voltage signals are output through the full-bridge strain circuit 11 based on weak changes of resistance values of the strain gauges, and further the stress condition of the torque sensor is obtained based on analysis of a processing module.

The output end of the full-bridge strain circuit 11 is connected with the input end of the amplifying circuit 12, so that the voltage signal output by the full-bridge strain circuit 11 is amplified by the amplifying circuit.

Since the resistance value of the strain gauge is usually weak due to stress, the voltage change caused by the change is also very weak, and the voltage change is usually in the uV level, the voltage signal needs to be amplified by an amplifying circuit.

An output of the amplifying circuit 12 is connected to an input of the filter 13.

Based on the above, since the voltage variation is very weak, the white noise of the system is inevitably caused during the sampling and amplifying process of the voltage signal, which results in a reduction in the sampling accuracy of the voltage signal, the amplified voltage signal can be filtered by the filter 13.

Specifically, the filter may be any filter which can perform the above-described filtering action now or developed in the future, as required.

In a preferred embodiment, the filter employs a second order active butterworth filter.

Since the noise signal of the system is a high-frequency signal in the frequency domain, the second-order active Butterworth filter is also called a maximum flattening filter, so that the voltage signal amplitude can be ensured to be unchanged to the greatest extent in the passband, the noise signal can be attenuated rapidly (for example, 40 dB/dec) in the passband, and the noise signal of high-frequency components can be effectively filtered on the premise of ensuring that the original signal data amplitude is unchanged and the phase is not lagged.

The output of the filter 13 is connected to the input of the ADC 14.

The filtered voltage signal is sent to the ADC14, so that the analog voltage signal may be converted into a digital voltage signal, and the digital electronic signal may be further sent to a back-end processing module, where the back-end processing module obtains a corresponding torque value according to the voltage signal based on a pre-calibration result.

The output end of the first voltage stabilizing unit 151 is connected to the voltage input end of the full-bridge strain circuit 11, and is used for providing a first voltage stabilization for the full-bridge strain circuit 11.

In one embodiment, the input terminal of the first voltage stabilizing unit 151 is connected to an external power source, and the external power source is stabilized to supply power to the full-bridge strain circuit 11.

In general, an external input power supply is often unstable due to interference of external noise, and based on equation (1) described in the following embodiment, if the input voltage fluctuates, the bridge output also fluctuates, and the change of the voltage output cannot reflect the actual situation that the strain gauge is subjected to torque, and by setting the first voltage stabilizing unit, a fixed voltage reference of the full-bridge strain circuit is given to ensure that the voltage input to the full-bridge strain circuit is fixed and stable.

The output terminal of the second voltage stabilizing unit 152 is connected to the voltage input terminal of the amplifying circuit, and is used for providing the second voltage stabilizing for the amplifying circuit.

By adopting the second voltage stabilizing unit, the voltage output to the amplifying circuit 11 can be stabilized at a fixed reference value, which is beneficial to improving the acquisition precision of the signal acquisition circuit in the embodiment of the utility model.

The embodiment of the utility model reads the weak voltage electric signal corresponding to the strain resistance change by adopting the full-bridge strain circuit; amplifying the weak voltage signal through an amplifying circuit; the amplified voltage signal is filtered through a filter, so that the noise signal of high-frequency components is effectively filtered on the premise of ensuring that the amplitude of the original signal data is unchanged and the phase is not lagged; and the voltage analog signal is converted into a digital signal through the ADC module, so that the measurement accuracy of the collected weak signal is improved, and the reliability of the circuit performance is ensured.

In one embodiment, the first voltage stabilizing unit 151 may include a first voltage stabilizing chip, and by adopting the first voltage stabilizing chip, the overall circuit structure may be made simpler.

Specifically, the first voltage stabilizing chip may be, but is not limited to: high-precision voltage stabilizing chips such as LMV431BIMFX, LMV431IM5, LMV431AIZ and the like. In a preferred real time, the first voltage stabilizing chip is LMV431BIMFX, LMV431IM5, LMV431AIZ, so that the full bridge strain circuit 11 can be better implemented to provide a stable voltage.

According to the embodiment of the utility model, the voltage output to the full-bridge strain circuit 11 can be stabilized at a preset value (for example, 25V) by adopting the adjustable voltage reference chip, so that the voltage precision is higher.

As shown in fig. 3, fig. 3 is a circuit diagram of an embodiment of the first voltage stabilizing unit provided by the present utility model.

In one embodiment, the first voltage stabilizing unit 151 includes: the current limiting resistor R31, the first voltage stabilizing chip U1 (preferably, the high-precision voltage stabilizing chip described in the above embodiment is used), the first resistor R32, and the second resistor R33.

The cathode of the voltage stabilizing chip U1 is connected in series with a current limiting resistor R31 so as to limit the current through the resistor R31; the anode is grounded; the reference electrode is connected to one end of the second resistor R33 and one end of the first resistor R32, respectively.

The other end of the second resistor R33 is grounded; the other end of the first resistor R32 is connected with the cathode of the voltage stabilizing chip U1.

Vout＝Vref(1+R31/R32)+Iref/R1

Thus, the regulated value Vout output by the first regulated unit can be adjusted within a preset range based on the adjustment of the resistance values of the first resistor R31 and the second resistor R32.

Further, in one embodiment, based on the foregoing embodiment, in order to make the input first voltage stabilizing unit voltage 30V and the output voltage stabilizing voltage 25V, the resistance values of the resistors may be set as follows:

Vka＝25V，R31＝100，Input＝30V，R32＝11K，R33＝1K。

by the first voltage stabilizing unit U1 of the circuit configuration described in the above embodiment, the input voltage can be stabilized.

In one embodiment, the second voltage stabilizing unit 152 may include a second voltage stabilizing chip, and by using the second voltage stabilizing chip, the overall circuit structure may be made simpler.

Specifically, the second voltage stabilizing chip may be, but is not limited to: high-precision voltage stabilizing chips such as LM4040C25FTA, ADR381 ARTY-REEL 7, MAX6071BAUT25+T and the like.

By adopting the high-precision voltage stabilizing chip, the voltage output to the amplifying circuit 11 can be stabilized at a fixed reference value, which is beneficial to improving the acquisition precision of the signal acquisition circuit in the embodiment of the utility model.

As shown in fig. 4, fig. 4 is a schematic circuit diagram of an embodiment of the second voltage stabilizing unit and the amplifier provided by the present utility model.

In one embodiment, the second voltage stabilizing unit 152 is configured to input bias voltage stabilizing to the amplifying circuit 12.

Since the voltage output by the full-bridge strain circuit 11 is an ac signal, but the whole sampling system is dc-powered, in order to ensure that the signal is not distorted, the ac signal needs to be converted into a dc signal. In one embodiment, a more convenient approach is to add a bias to the signal, such as: the supply voltage of the amplifying circuit is 5V, so by increasing a bias voltage of one path of 2.5V on the amplifying circuit 11, the voltage signal output by the amplifying circuit is ensured to be positive.

The output voltage formula of the amplifying circuit is as follows:

V _OUT ＝G×(V _IN+ -V _IN- )+V _REF (2)

let Vref be 2.5V, G be the voltage gain, (VIN+) - (VIN-) be the bridge output voltage. Therefore, the first voltage stabilizing unit can enable the output voltage of the amplifying circuit not to be influenced by external interference, and the output voltage can reflect the change of the input voltage.

In one embodiment, the second voltage stabilizing unit 152 includes: the second voltage stabilizing chip and the voltage dividing circuit.

The voltage dividing circuit is connected with the second voltage stabilizing chip, so that the second voltage stabilizing unit outputs the bias voltage (for example, 2.5V) of the amplifying circuit by the second voltage stabilizing chip based on the input external power supply voltage (for example, 5V).

For example, as shown in fig. 4, taking the example that the second voltage stabilizing unit includes the voltage stabilizing chip ADR03ARZ, the voltage-stabilizing bias voltage of 2.5V can be output to the amplifying circuit 12 after being divided by the second voltage stabilizing chip and the voltage dividing circuit.

In one embodiment, the power conversion module further comprises: the boosting unit 153.

Further, in one embodiment, the voltage boosting unit 153 includes a voltage boosting chip, and by employing the voltage boosting chip, the overall circuit structure can be made simpler.

An output terminal of the voltage boosting unit 153 is connected to an input terminal of the first voltage stabilizing unit 151. In one embodiment, the input end of the voltage boosting unit 153 is connected to an external power source, so that the voltage boosting unit 153 is connected in series between the external power source and the first voltage stabilizing unit 151, and thus the voltage input by the external power source can be boosted by the voltage boosting unit and then stabilized by the first voltage stabilizing unit.

Specifically, the boost chip may be, but is not limited to: LT1054.

In a preferred embodiment, the boost chip is LT1054. The chip is a capacitance type boost chip, is different from an inductance type boost circuit, has small noise relative to the inductance type boost circuit, can not generate new interference to a sampling circuit, has few required peripheral devices and occupies little PCB space, and is suitable for the development of compact sensors.

In one embodiment, the 5V voltage inputted from the external power source may be raised to 35V by the voltage raising unit 153; then, the voltage is stabilized at 30V through the first voltage stabilizing unit 151, so that the accuracy of signal acquisition is improved under the condition that the system requirement is met.

Based on the voltage signal calculation formula (1) of the full-bridge strain circuit 11 described in the following embodiment, it can be known that after the power supply voltage U is raised to several times of the allowable range by the voltage-raising unit, the output voltage U' will be amplified in equal proportion on the premise of no change in noise level.

As shown in fig. 5, fig. 5 is a circuit diagram of one embodiment of the booster unit provided by the present utility model.

In one embodiment, the boosting unit 153 includes: a base voltage inversion module 1531 and a voltage inverse multiplication module 1532.

The basic voltage inversion module 1531 inverts and boosts the input voltage and sends the boosted voltage to the voltage inverse multiplication module 1532, and the voltage inverse multiplication module 1532 inversely multiplies and outputs the voltage boosted by the basic voltage inversion module 1531, so that the boosting can be better realized.

Such as: for 5V input voltage, the voltage is boosted by the basic voltage inversion module 1531 to obtain-15V, and then is multiplied by the voltage inverse multiplication module 1532 to output 30V voltage.

In one embodiment, the base voltage inversion module 1531 includes: the first boost chip U2 (for example, LT 1054), the first polar capacitor E1, the second polar capacitor E2, the third polar capacitor E3, the capacitor C1, the first resistor R51 and the second resistor R52.

The CAP+ of the first boost chip U2 is connected to the pin-CAP through a first polarity capacitor E1; the VREF pin is connected with the FB/SHDN pin through a first resistor R51; the pin V+ is connected with the input voltage Vin and grounded through a second polar capacitor E2; the grounding pin GND is grounded; the Vout pin is grounded through a third polar capacitor E3, is connected with a voltage output end Vout through a second resistor R52 and a capacitor C1, and is connected with the FB/SHDN pin through the second resistor R52.

Illustratively, based on the formula (2)

When r51=1k, r52=13.4k, e1=10μf, e2=2μf, e3=100deg.μf, c1=0.002 Mf, and vin=5v, the output voltage vout= -15V after the inversion and boosting by the first boosting module 1531.

In one embodiment, the voltage inverse multiplication module 1532 includes: the second boost chip U3 (for example, LT 1054), fourth polar capacitor E4, fifth polar capacitor E5, sixth polar capacitor E6, transistor Q51, and third resistor R53.

The pin CAP+ of the second boost chip U3 is connected to the pin-CAP through a fourth polar capacitor E4; the Vout pin is connected with the emitter of the transistor Q51, and the Vout pin of the boost chip U3 is prevented from being pulled to be above the GND pin through the transistor Q51 during starting; the ground pin GND is connected to the input voltage Vin output by the first boost module 1531 and is further connected to ground by the fifth polarity capacitor E5; the V+ pin is grounded and then connected with one end of an output load (the first voltage stabilizing unit can be used here); the other end of the output load is connected with the collector of the transistor Q51.

One end of the sixth polar capacitor E6 is connected with the Vout pin of the boost chip U3; the other end is connected with the input voltage Vin.

The base of the transistor 51 is connected to the input voltage Vin output through the basic voltage inversion module 1531 via the third resistor R53, so as to provide a sufficient driving current for the base of the transistor via the third resistor R53.

Illustratively, e4=100 μf, e5=2 μf, e6=100 mf, vin ranging from-3.5V to-15V; vout=2vin+u3 voltage loss+transistor Q51 saturation voltage. Such as: vin= -15V (first boost module output voltage), vout=30v.

By adopting the voltage boosting unit including the circuit configuration described in the above embodiment, voltage boosting can be better achieved based on the cooperation of the basic voltage inversion module 1531 and the voltage inverse multiplication module 1532. Such as: 5V voltage is input, inverted and boosted by the basic voltage inversion module to obtain-15V, and inverted and multiplied by the voltage inverse multiplication module to finally output 30V voltage.

As shown in fig. 6A and 6B, fig. 6A is a schematic structural view of one embodiment of a four strain gage arrangement provided by the present utility model; FIG. 6B is a schematic diagram of a frame structure of one embodiment of a full bridge strain circuit corresponding to the strain gauge arrangement of FIG. 6A in accordance with the present utility model.

In one embodiment, the full bridge strain circuit includes four legs; each bridge arm is connected with a strain gauge; the four bridge arms are connected end to end. When the strain gauge is stressed, the resistance value of the strain gauge connected with each bridge arm can be changed slightly, and a corresponding voltage signal is output based on the formula (1).

When the strain gage is not subjected to external force, the bridge is balanced, and U' =0v.

In one embodiment, the four sets of strain gages S1, S2, S3, S4 may be uniformly distributed over the spring beam in the manner illustrated in FIG. 6A.

Accordingly, the full bridge strain circuit corresponding to the strain gauge is shown in fig. 6B, wherein the variable resistance generated by deformation of the S1 strain gauge is R1, the variable resistance generated by deformation of the S2 strain gauge is R2, the variable resistance generated by deformation of the S3 strain gauge is R3, and the variable resistance generated by deformation of the S4 strain gauge is R4. Accordingly, based on the formula (1), a corresponding voltage signal can be output, and then based on a calibration result of the sensor formed by the strain gauge in advance, a corresponding moment can be obtained based on the voltage value.

As shown in fig. 7A and 7B, fig. 7A is a schematic structural view of one embodiment of an eight strain gage arrangement provided by the present utility model; FIG. 7B is a schematic diagram of a frame structure of one embodiment of a full bridge strain circuit corresponding to the strain gauge arrangement of FIG. 7A in accordance with the present utility model.

In one embodiment, the full bridge strain circuit includes four legs; each bridge arm is connected with two strain gauges; the resistance values of the strain gauges of each bridge arm and two adjacent bridge arms are in the same direction, and the resistance values of the strain gauges of the opposite bridge arms are in the same direction.

Illustratively, the eight sets of strain gages S1, S2, S3, S4, S5, S6, S7, S8 may be uniformly distributed over the spring beam in the manner illustrated in FIG. 7A.

Therefore, as shown in fig. 7B, two strain gauges are connected to each bridge arm of the full-bridge strain circuit corresponding to the strain gauges, so that the bridge is multiplied, if the strain gauges on two adjacent bridge arms of the bridge circuit are equal in change number, the resistance values of the strain gauges on the two opposite arms are equal in number, and the voltage and the sensitivity of the output end of the full-bridge strain circuit are 4 times that of the half-bridge single arm.

The embodiment of the utility model is based on the formula (1), if the power supply voltage of the bridge is increased, the quality of the acquired real signal can be greatly improved under the condition that the strain gauge is subjected to the same deformation. Such as: under the condition that the resistance value of the strain gauge is unchanged, the input external power supply can be increased by 6 times, the output of the bridge is also increased by 6 times, so that the real signal quality can be greatly improved without being covered by noise, and the signal-to-noise ratio of the signal is also increased by 6 times.

In one embodiment, amplifying circuit 12 may be an instrumentation amplifier (e.g., as shown in FIG. 4). The instrument amplifier is a precise differential voltage amplifier, has the characteristics of high common mode rejection ratio, high input impedance, low noise, low drift and the like, and can set voltage gain through an external resistor, so that the instrument amplifier is very suitable for being used in the signal acquisition circuit; in addition, any desired amplifying circuit may be used as needed.

Based on the signal acquisition circuit of the torque described in the above embodiment, the embodiment of the present utility model further provides a sensing device, where the sensing device includes the signal acquisition circuit of the torque described in the above embodiment.

The embodiment of the utility model reads the weak voltage electric signal corresponding to the strain resistance change by adopting the full-bridge strain circuit; amplifying the weak voltage signal through an amplifying circuit; the amplified voltage signal is filtered through a filter, so that the noise signal of high-frequency components is effectively filtered on the premise of ensuring that the amplitude of the original signal data is unchanged and the phase is not lagged; and then the voltage analog signal is converted into a digital signal through the ADC module, so that the accuracy of strain feedback signal acquisition is improved.

Based on the sensing device described in the above embodiments, the embodiment of the present utility model further provides a robot including a plurality of joints and a sensing device for measuring torque of each joint.

Specifically, the spring beam of the sensing device is attached to the articular surface.

Such robots include, but are not limited to: a humanoid robot or an industrial robot, a medical rehabilitation/care robot.

It is apparent that the above-described embodiments are only some embodiments of the present utility model, but not all embodiments, and the preferred embodiments of the present utility model are shown in the drawings, which do not limit the scope of the patent claims. This utility model may be embodied in many different forms, but rather, embodiments are provided in order to provide a thorough and complete understanding of the present disclosure. Although the utility model has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing description, or equivalents may be substituted for elements thereof. All equivalent structures made by the content of the specification and the drawings of the utility model are directly or indirectly applied to other related technical fields, and are also within the scope of the utility model.

Claims

1. A signal acquisition circuit of moment of torsion for carry out signal acquisition to the joint moment of torsion of robot, characterized in that includes: the full-bridge strain circuit, the amplifying circuit, the filter, the analog-to-digital converter and the power supply conversion module; the power conversion module includes: a first voltage stabilizing unit and a second voltage stabilizing unit;

2. The torque signal acquisition circuit of claim 1, wherein the power conversion module further comprises a boost unit;

3. The torque signal acquisition circuit of claim 2, wherein the boost unit comprises an LT1054 boost chip.

4. The torque signal acquisition circuit of claim 2, wherein the boost unit comprises: the basic voltage inversion module and the voltage inverse multiplication module;

5. The torque signal acquisition circuit according to claim 1 or 2, wherein the first voltage stabilizing unit includes: a high-precision voltage stabilizing chip; and/or

6. The signal acquisition circuit of torque according to claim 2, wherein the boosting unit boosts up to 30V; the first voltage stabilizing unit is used for stabilizing the voltage to 25V.

7. The signal acquisition circuit of torque according to claim 1 or 2, wherein,

the second voltage stabilizing unit comprises an adjustable voltage reference chip; and/or

8. The torque signal acquisition circuit of claim 1 or 2, wherein the full-bridge strain circuit comprises four legs; each bridge arm is connected with a strain gauge; or (b)

9. A sensing device comprising a strain gauge and a signal acquisition circuit for torque according to any one of claims 1 to 8.

10. A robot comprising the sensing device of claim 9.