Dual-channel angular velocity sensor

Abstract

FIELD: gyroscopic instrumentation.SUBSTANCE: invention can be used as a two-channel angular velocity meter, for example, in the construction of strapdown orientation and navigation systems, as well as in indicator stabilization systems. The two-channel angular velocity sensor (Fig. 1) is based on a gyroscope with a spherical support. On base 1, stators of inductive type angle sensors are fixed, two (2 and 3), (4 and 5) for each measurement axis, which are connected according to a differential circuit, and stators of electromagnetic type force sensors, two for each control channel (6 and 7), (8 and 9). Their rotor is ferrite ring 12, mounted in rotor 10 of the gyromotor. In order to measure angular velocities coinciding in direction with the axes of the force sensors, the signals from the angle sensors, passing through signal converters 13 and 14, are fed to the first and second inputs of microcontroller 15, in which the problems of generating control PWM signals for four force sensors (6 and 7), (8 and 9) are solved: coordinate transformation of the output signals from the angle sensors, software construction of correction links and generation of output signals, which through the first and second output ports of the microcontroller are fed, respectively, to the amplifiers of the first (16) and second (17) channels, the outputs of which are connected to the signal inputs of the analogue switches of the first (18) and second (19) channels, the control inputs of which are connected to the third and fourth output ports of microcontroller (15), respectively, wherein the first and second outputs of the analogue switch of the first channel (18) are connected to the first and second force sensors, the first and second outputs of the analogue switch of the second channel (19) are connected to the third and fourth force sensors, and signals proportional to angular velocities are generated at the fifth and sixth output ports of the microcontroller, the seventh output port of which is used to connect a personal computer 20.EFFECT: obtaining a linear characteristic of control loops, simplifying the construction of feedback circuits of a two-channel angular velocity sensor, and increasing the accuracy of measuring angular velocities.1 cl, 3 dwg

Description

[0001] The invention relates to gyroscopic instrument making and can be used as a two-channel angular velocity meter, for example, in the construction of strapdown orientation and navigation systems, as well as in indicator stabilization systems.

[0002] A gyroscope is known (A.S. No. 431808, Bulletin No. 23 dated 08 / 20 / 2005) containing a housing, a gyromotor, a gimbal suspension, angle sensors and torque sensors rotated relative to each other by 90° around the longitudinal axis of the gyroscope, on the basis of which a two-channel angular velocity sensor can be constructed using feedback.

[0003] The main disadvantage of this gyroscope is the presence of a gimbal suspension, which causes significant drift of the gyroscope due to the need to use current leads to supply power to the windings of the gyromotor, angle sensors and torque sensors and ball bearings - to ensure the rotation of the gimbal frames, which will lead to an increase in the sensitivity threshold and, accordingly, to a decrease in the accuracy of measuring angular velocities.

[0004] Also known is a gyroscope (US Patent No. 3517562, NKI 74 / 5.6, IPC G01C 19 / 28, issued June 30, 1970), comprising a housing with a hermetically sealed lid, a gyromotor, a rotor on a spherical ball bearing support, mutually inductive angle sensors and electromagnetic torque sensors. The gyromotor stator consists of two laminated packages separated by a non-magnetic element and a winding, the turns of which wrap around both packages. In addition to its main function, the gyromotor winding also functions as the primary winding of the mutually inductive angle sensor. The secondary windings of the angle sensors are wound separately on each package, with each pair of windings geometrically shifted relative to each other by 90 degrees, which allows for measurements along two axes. The torque sensors are structurally similar to the angle sensors and are geometrically shifted relative to them by 180 degrees.

[0005] The disadvantage of this gyroscope is the nonlinear (quadratic) characteristic of the torque sensor, which does not allow its use as a sensitive element of a gyrostabilizer or a two-channel angular velocity meter without the use of additional computing devices that linearize the static characteristic of the torque sensor.

[0006] The prototype is a dual-channel angular velocity sensor built on a dual-channel gyroscope, the rotor of which is suspended on a spherical ball bearing support (RU Patent No. 2725880. Bulletin No. 19 dated 07.07.2020), which is most suitable for upgrading a dual-channel angular velocity sensor with a linear output characteristic for the measured angular velocity.

[0007] The two-channel angular velocity sensor comprises a two-channel gyroscope with a spherical support for the suspension of a bell-type gyromotor rotor, on the base of which, for each measurement channel, two angle sensors are installed diametrically on mutually perpendicular axes, the outputs of which are connected to the first and second inputs of the differential adders, and for each control channel, two force sensors are installed diametrically on mutually perpendicular axes, wherein there is an angle equal to 45° between the axes of the placement of the angle sensors and the force sensors, wherein the control channels additionally comprise first and second coordinate converters, a reference voltage source, first and second control channel amplifiers, first to fourth adders, first to fourth scaling resistors and two output summing amplifiers, wherein the outputs of the first and second differential adders are connected to the first and second inputs of the coordinate converters,the outputs of which are connected through the first and second control channel amplifiers to the second inputs of the first and second and, respectively, the third and fourth adders, with the first input of which a reference voltage source is connected, wherein the outputs of the first and second adders are connected through the first and second scaling resistors, respectively, to the force sensors of the first control channel, and the outputs of the third and fourth adders are connected through the third and fourth scaling resistors, respectively, to the force sensors of the second control channel, and the output signals of the two-channel angular velocity sensor are formed, for the first control channel, as the difference in the voltages taken from the first and second scaling resistors and supplied to the first and second inputs of the first output summing amplifier, and for the second control channel - as the difference in the voltages taken from the third and fourth scaling resistors and supplied to the first and second inputs of the second output summing amplifier.

[0008] The disadvantage of the prototype is the complexity (bulkiness) of constructing feedback circuits from analog elements, as well as the lack of nodes in the form of correction links that would ensure the stability and specified quality of operation of the two-channel angular velocity sensor, which, ultimately, will complicate the setup of feedback circuits and lead to a decrease in measurement accuracy.

[0009] The technical result of the invention is to obtain a linear characteristic of control loops by introducing pulse-width control signals, simplifying the construction of feedback circuits of a two-channel angular velocity sensor by replacing some analog elements with software elements implemented in a microcontroller, which, on the one hand, will simplify the setting of parameters of the correction links in feedback circuits, and on the other hand, will increase the accuracy of measuring angular velocities.

[0010] The technical result is achieved in that in a two-channel angular velocity sensor containing a gyroscope with a spherical support for the suspension of a bell-type gyromotor rotor, on the base of which, along each measurement channel, two differentially connected angle sensors are installed diametrically on mutually perpendicular axes, the outputs of which are connected to the first and second signal converters, and along each control channel, two force sensors are installed diametrically on mutually perpendicular axes, wherein between the axes of the placement of the angle sensors and the force sensors there is an angle equal to 45°, what is new is that the device contains a microcontroller, to the first and second input ports of which the first and second signal converters are connected, wherein the first and second output ports of the microcontroller are connected respectively to the amplifiers of the first and second channels, the outputs of which are connected to the signal inputs of the analog switches of the first and second channels,the control inputs of which are connected to the third and fourth output ports of the microcontroller, respectively, wherein the first and second outputs of the analog switch of the first channel are connected to the first and second force sensors, the first and second outputs of the analog switch of the second channel are connected to the third and fourth force sensors, and signals proportional to the angular velocities are generated on the fifth and sixth output ports of the microcontroller, the seventh output port of which is used to connect a personal computer.

[0011] The essence of the invention is explained by the figures, where Fig. 1 is a structural and kinematic diagram of a two-channel angular velocity sensor, shown on two sheets; Fig. 2 is the relative position of the coordinate systems, explaining the operation of the coordinate converter; Fig. 3 is the arrangement of the force sensors with an explanation of the creation of control moments.

[0012] In Fig. 1 - Fig. 3 the following designations are used:

[0013] 1 - body (base);

[0014] 2, 3 - the first and second angle sensors measuring the angle of rotation of the rotor relative to the Y1 axis;

[0015] 4, 5 - the third and fourth angle sensors measuring the angle of rotation of the rotor relative to the Z1 axis;

[0016] 6, 7 - the first and second force sensors that generate torque relative to the Y axis (for the second control channel);

[0017] 8, 9 - the third and fourth force sensors that generate torque relative to the Z axis (for the first control channel);

[0018] 10 - gyroscope rotor (engine not shown);

[0019] 11 - spherical ball bearing support;

[0020] 12 - rotor of angle sensors and force sensors;

[0021] 13, 14 - the first and second signal converters of angle sensors 2 and 3, 4 and 5, respectively;

[0022] 15 - microcontroller;

[0023] 16 - first channel amplifier;

[0024] 17 - second channel amplifier;

[0025] 18 - first channel analog switch;

[0026] 19 - second channel analog switch;

[0027] 20 - personal computer;

[0028] H - kinetic moment of the gyroscope rotor;

[0029] - measurement axes determined by the position of the angle sensors;

[0030] - the control axes determined by the position of the force sensors are the input axes for the angular velocities , first and second channels;

[0031] - angles of rotation of the rotor relative to the base along the measurement axes respectively;

[0032] - angles of rotation of the rotor relative to the base along the control axes respectively;

[0033] - angular velocities of rotation of the rotor relative to the base along the control axes respectively;

[0034] - small vectors interpreting the rotation of the rotor relative to the base along the measurement axes respectively;

[0035] - small vectors interpreting the rotation of the rotor relative to the base along the control axes respectively;

[0036] L- distance between force sensors and suspension center;

[0037] , - voltage at the output of the first and second signal converters; control voltages of the microcontroller for the first and second channels, respectively;

[0038] control voltages of the microcontroller for the first and second analog switches, respectively;

[0039] voltages for force sensors;

[0040] control currents in force sensors;

[0041] , - output voltages of the two-channel angular velocity sensor for the first and second channels;

[0042] - active resistance of the force sensor winding;

[0043] - transmission coefficient of force sensors;

[0044] , - measured angular velocities on the first and second channels;

[0045] - electromagnetic forces generated by force sensors 6 and 7, respectively;

[0046] - electromagnetic forces generated by force sensors 8 and 9, respectively;

[0047] - moments created by forces relative to the axis ;

[0048] - moments created by forces relative to the axis .

[0049] The dual-channel angular velocity sensor is based on a spherical-bearing gyroscope, which is shown in Fig. 1 in a simplified form sufficient to explain the essence of the invention. Stators of inductive angle sensors (end-mounted) and stators of electromagnetic force sensors are mounted on base 1. Angle sensors 2 and 3 measure the rotation angle. around the axis , and angle sensors 4 and 5 - the rotation angle around the axis The force sensors are paired to form moment sensors and are rotated by an angle relative to the angle sensors. . In this case, the force sensor 6 creates a moment , and force sensor 7 creates a moment relative to the axis for the first control channel, force sensor 8 creates a moment , and the force sensor 9 creates a moment relative to the axis second control channel. The rotor of the gyroscope 10 rotates in a spherical ball bearing support 11 (the gyromotor is not shown conditionally). A ring 12 (for example, made of ferrite) is mounted in the rotor 10, which is simultaneously the rotor of the angle sensors 2-5 and the rotor of the force sensors 6-9. The angle sensors 2-3 and 4-5 are connected according to a differential circuit to increase the steepness of the output signal, and their outputs are connected to the first and second signal converters 13 and 14, which consist of phase-sensitive amplifiers with scaling. To form the feedback loops, a microcontroller 15 is used, to the first and second input ports of which the outputs of the first 13 and second 14 signal converters are connected, respectively. In this case, the first and second output ports of the microcontroller 15 are connected, respectively, to the amplifiers of the first 16 second 17 channels, the outputs of which are connected to the signal inputs of the analog switches of the first 18 and second 19 channels.The control inputs of switches 18 and 19 are connected respectively to the third and fourth output ports of microcontroller 15. In this case, the first and second signal outputs of analog switch 18 are connected to the first 6 and second 7 force sensors, and the first and second signal outputs of analog switch 19 are connected to the third 8 and fourth 9 force sensors.

[0050] Output information on measured angular velocities is sent to consumers from the fifth and sixth output ports of microcontroller 15. The seventh output port is used to connect a personal computer (PC), which is used to load programs into the microcontroller for setup and calibration. All input ports of microcontroller 15 have built-in analog-to-digital converters, and the first and second output ports provide control voltages. pulse width modulation (PWM), and the third and fourth are digital signals (for example, logical "1" or logical "0") to control the first 18 and second 19 analog switches.

[0051] When the input angular velocities are applied And the body of the device 1 deviates relative to the rotor 10 of the gyroscope (the angular momentum vector maintains direction in inertial space) and, accordingly, the rotor 12 of angle sensors 2-3 and 4-5. The deviations of the housing are determined by the angles relative to the measurement axes , are recorded by angle sensors 2-3 and 4-5 and are fed to the first and second signal converters 13 and 14

[0052] (1)

[0053] where steepness of angle sensors and gain of converter.

[0054] Voltage And are received at the first and second input ports of the microcontroller 15 and are processed by the program in the following sequence.

[0055] 1. Voltage And The signals from the first and second input ports are converted into digital code in the built-in ADC and, in parallel, the following actions are performed by the program written into the microcontroller memory:

[0056] 1.1.Functional transformation according to the coordinate converter diagram (see Fig. 2), i.e. voltages proportional to angles relative to the measurement axes , are converted into voltages proportional to the angles , relative to the control axes

[0057] (2)

[0058] where And voltage of the algorithmic coordinate converter (we must understand their digital analogue, i.e. binary code); coordinate transformation coefficient.

[0059] 1.2. Logical signals are generated , for example, in this form

[0060] (3)

[0061] 2. The voltages of the algorithmic coordinate converter pass through digital correction filters, the structure and parameters of which were obtained during the design of the correction circuits

[0062] (4)

[0063] where voltage of digital correction filters; transfer functions of correction filters (for correction circuits of a two-channel angular velocity sensor, they are the same for each channel); (a notation for the inverse Laplace transform).

[0064] 3. Since the control action in microcontroller 15 is formed by the pulse-width modulation method, the duration of the control pulses And will be proportional to the voltages respectively:

[0065] (5)

[0066] where - proportionality coefficient for control.

[0067] In this case, the output control voltages of the microcontroller are determined through the effective value of the PWM signal voltage over the period:

[0068] (6)

[0069] where , - effective values ​​of control voltages, - high logic level voltage from the microcontroller (usually equal to the supply voltage of the microcontroller), and the duration of the PWM signal pulses And , - PWM signal period.

[0070] Then the PWM control signals are sent to the inputs of the amplifiers of the first 16 and second 17 channels, the outputs of which are connected to the signal inputs of the first 18 and second 19 analog switches. The force sensors are controlled as follows depending on the voltages .

[0071] Let's look at the explanations and operation of the gyroscope and program when measuring angular velocities.

[0072] First control channel - measurement .

[0073] Let's assume that an object has an angular velocity .

[0074] The gyroscope control system shall operate in such a way that the angular velocity of precession of the angular momentum vector was directed along the vector of the measured angular velocity (in this case directed towards ).

[0075] Then it will form And

[0076] In this case, force sensor 7 creates a force (force sensor 6 does not create a force)

[0077]

[0078] and accordingly the moment

[0079] (7)

[0080] If , then it will be formed And

[0081] At the same time, force sensor 6 will create a force

[0082]

[0083] and accordingly the moment

[0084] (8)

[0085] Second control channel - measurement .

[0086] Let's assume that an object has an angular velocity .

[0087] The gyroscope control system shall operate in such a way that the angular velocity of precession of the angular momentum vector was directed along the vector of the measured angular velocity (in this case directed in the direction ).

[0088] Then it will form And

[0089] In this case, force sensor 8 will create a force (force sensor 9 will not create a force)

[0090]

[0091] and accordingly the moment

[0092] (9)

[0093] If , then it will be formed And

[0094] At the same time, force sensor 9 will create a force

[0095]

[0096] and accordingly the moment

[0097] (10)

[0098] Since in (8) the parameters are considered constant, then the values ​​of the control moments will have a linear dependence on the duration of the PWM signal pulses And .

[0099] To explain the measurement of angular velocities by a two-channel angular velocity sensor, we will compose, in accordance with Fig. 3, the precession equations of the first and second control channels relative to the axes respectively

[0100] ; (11)

[0101] . (12)

[0102] In steady state, when are equal to zero, the measured angular velocities are determined from equations (11) and (12) And

[0103] ; (13)

[0104] . (14)

[0105] Equations (13) and (14) are used when executing the program on the microcontroller 15 both to evaluate the accuracy of measuring the input angular velocities and to output information in digital or analog form. In this case, the output voltages And are formed in accordance with (13) and (14):

[0106]

[0107]

[0108] where - scale factor for output signals And .

[0109] Thus, despite the quadratic dependence of the forces generated by the force sensors on the current, the output characteristics for angular velocities have a linear dependence.

[0110] With the given parameters, the operation of a dual-channel angular velocity sensor was simulated using the precession and full models under step and harmonic input angular velocities. The simulation confirmed good agreement with theoretical predictions.

[0111] Thus, using the advantages of a gyroscope with a rotor suspended on a spherical ball bearing (small dimensions and cost compared to dynamically tuned gyroscopes, averaging of drift moments), in the proposed device, due to the use of a microcontroller, a linear dependence of the output voltage on the measured angular velocities is constructed, which simplifies the use of a two-channel angular velocity sensor in various stabilization and control systems.

Claims

A two-channel angular velocity sensor comprising a gyroscope with a spherical support for the suspension of a bell-type gyromotor rotor, on the base of which, for each measurement channel, two differentially connected angle sensors are mounted diametrically on mutually perpendicular axes, the outputs of which are connected to the first and second signal converters, and for each control channel, two force sensors are mounted diametrically on mutually perpendicular axes, wherein between the axes of the placement of the angle sensors and the force sensors there is an angle equal to 45°, characterized in that the device comprises a microcontroller, to the first and second input ports of which the first and second signal converters are connected, wherein the first and second output ports of the microcontroller are connected respectively to the amplifiers of the first and second channels, the outputs of which are connected to the signal inputs of the analog switches of the first and second channels,the control inputs of which are connected to the third and fourth output ports of the microcontroller, respectively, wherein the first and second outputs of the analog switch of the first channel are connected to the first and second force sensors, the first and second outputs of the analog switch of the second channel are connected to the third and fourth force sensors, and signals proportional to the angular velocities are generated on the fifth and sixth output ports of the microcontroller, the seventh output port of which is used to connect a personal computer.

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