RU2701459C1 - Robot manipulator control device - Google Patents

Abstract

FIELD: robotics.

SUBSTANCE: robot manipulator control device comprises a rotation angle sensor, a comparison unit (adder), six amplifiers, two integrators, an actuator connected in a certain manner.

EFFECT: faster operation, reduced error of positioning, simple device and broader functional capabilities.

1 cl, 4 dwg

Description

The device relates to the field of robotics and can be used to automate production processes.

The technical result is to increase performance, reduce positioning errors, simplify the device and expand the functionality.

The well-known "Simulator of an automatic system for robust control of periodic modes of a two-link robot manipulator" (Patent for PM No. 125360, IPC G05B 13/02, publ. 02/27/2013), containing a nonlinear non-stationary control object, sets of driving actions, local combined robust regulators (ЛР_1 and ЛР_2), local state observers (НС_1 and НС_2), first, second, third, fourth, fourth, fifth, sixth oscilloscopes, plotter, first and second blocks for setting coefficients, first, second, third and fourth blocks of summation, when this, the first output of the control object is simultaneously connected to the first input of the plotter and the second input of the first state observer (НС_1), the outputs of which are connected to the corresponding inputs of the first unit for setting the coefficients, as well as to the first, second and third inputs of the first local controller (ЛР_1); the outputs of the first unit for setting coefficients go to the corresponding inputs of the first summing unit, the output of which is connected to the second input of the second summing unit; the first input of the second summing block is connected to the output of the first block of the driving action, a signal from the output of which also goes to the input of the first oscilloscope; the output of the second summing unit is simultaneously connected to the fourth input of the first local controller (LR_1) and to the input of the second oscilloscope; the output of the first local controller (ЛР_1) is connected to the input of the third oscilloscope, to the first input of the control object, as well as to the first input of the first state observer (НС_1); the second output of the control object is simultaneously connected to the second input of the plotter and the first input of the second state observer (HC_2), the outputs of which are connected to the corresponding inputs of the second block for setting the coefficients, as well as to the first, second and third inputs of the second local controller (ЛР_2); the outputs of the second coefficient setting unit are connected to the corresponding inputs of the third summing unit, the output of which is connected to the second input of the fourth summing unit; the output of the second driver unit is connected to the first input of the fourth block of summation, which is also connected to the input of the fourth oscilloscope; the output of the fourth summing unit is connected to the input of the fifth oscilloscope and to the fourth input of the second local controller (ЛР_2); the output of which is connected to the input of the sixth oscilloscope, with the second input of the control object, as well as with the second input of the second observer (НС_2).

The disadvantage of this technical solution is the complexity of the device and the lack of speed due to the formation of the control action for different functions: the time for setting the control parameters of the manipulator links and their development by the engine, which is an order of magnitude longer than the correction signal for control error signals. In addition, this device is a simulator, and not a real device, subject to the influence of real disturbing moments, as a result of which uncontrolled increments of angular positioning appear. In this known device, an error is parried between a given position of the link and its evaluation, which does not reduce the positioning error of a real object.

A known system for planning the movement of a robot manipulator in an unknown dynamic environment (Patent for PM No. 83729, IPC G05J 13/00, published on 06/20/2008), containing infrared sensors, a unit for calculating the distance between each link of the robot manipulator and the nearest obstacle, the use of a fuzzy decision-making structure to determine the change in the angle of movement of each link of the robot manipulator during each program iteration, using the minimum distance between each link and the nearest m obstacle, as well as the difference between the current and target configurations of the links of the robot manipulator, characterized in that it further comprises a subsystem for classifying the locations of obstacles in the working area of the robot manipulator and the directions associated with the locations of obstacles in the form of movement of each link of the robot manipulator, consisting for a two-link robot manipulator of two hundred and fifty-six positions, based on the complete classification table, trained according to the method of back propagation of three errors a loyal neural network consisting of six inputs, forty neurons of the first hidden layer, twenty five neurons of the second hidden layer, two neurons of the output layer, the inputs of the three-layer neural network are the outputs of the encoding block, while the outputs of this network are used as inputs to the decoding block, two the output of the decoding unit is the final modified distance value between each link of the robot and the nearest obstacle, which are the inputs to the distance change calculation unit having two outputs using changes of the final modified distance values between each robot link and the obstacle, the final modified distance values between each robot link and the obstacle and their changes are inputs into the fuzzy decision-making structure consisting of two stages, the first stage includes the first pair of fuzzy blocks : one for the first link, the second for the second link of the two-link robot manipulator, the inputs for each fuzzy block of the first pair are represented by two parameters mi: the value of the difference between the target and current configurations, as well as the previous change in the angle of movement of each link of the robot manipulator, which provides internal feedback in the planning system for moving the robot manipulator in an unknown dynamic environment, the output of each fuzzy block of the first pair is a preliminary value the step of moving the corresponding link of the robot manipulator, which, together with the final modified value of the distance between each link of the robot manipulator and the closest obstacle, as well as changing the final modified value of the distance between each link of the robotic arm and the obstacle are used as inputs to the second stage of the fuzzy subsystem, represented by two fuzzy blocks, the outputs of the second pair of fuzzy blocks is the value of changing the angle of movement of each of the links of the robot the manipulator, the amplification factors by which are multiplied by the values of the change in the angle of movement of each link of the robot - the manipulator, the obtained values of this product The results are received on the actuator, the product of the amplification factors and changes in the angle of movement of the robot-manipulator links obtained during the previous computer iteration, providing external feedback, are used together with the target configuration values as inputs to the displacement planning system

The disadvantages of this technical solution is its complexity. Even considering not the entire robot manipulator in an unknown dynamic environment with obstacles, not only restricting the use of this utility model, but the termination of the utility model in one start of motion, and considering the given rotation angle with the actual one. The angular error is not quickly compensated, but gradually decreases at each step of the iteration, being additionally compared in the fuzzy decision-making subsystem with the measured distances between the links and the obstacle.

The closest technical solution is the “Robot manipulator control device (Patent for IZ No. 2230349, IPC G05B 11/00, G05J 13/00, publ. 10/27/2003), containing the first comparison unit, the first amplifier, the adder, connected in series a servo drive, an actuator, a rotation angle sensor, and also comprising a differentiation unit connected via a second amplifier to the second input of the adder, two nonlinear elements, a second comparison unit, two module selection units, an “I” circuit, an “NOT” circuit, six keys, a dial speed adjuster Assumption inverter, a second adder and a third amplifier, wherein

The output of the second comparison unit through the first non-linear element with a dead zone connected in series, the first module selection unit, the AND circuit, the NOT circuit is connected to the first input of the first key, the second input of which is connected in parallel with the first input of the second comparison unit, the output of the angle sensor the rotation is connected to the second input of the second comparison unit, to the first input of the second key, the output of which is parallel to the output of the third key connected to the input of the differentiation unit and the output of the angle sensor is connected also through the fourth key to the first input of the first comparison unit, the output of which is also connected to the first input of the third key, the output of the second nonlinear element through the second module selection unit is connected to the second input of the “I” circuit, the output of the third amplifier is connected to the first input of the fifth key, the output the fifth key in parallel with the output of the first key is connected to the second input of the first comparison unit, the output of the circuit is NOT connected also to the second inputs of the third and fourth keys, the output of the circuit And is also connected to the second inputs of the second of the fifth and fifth keys, the output of the position adjuster is connected to the first input of the second comparison unit, and the output of the speed adjuster is connected to the input of the second nonlinear element and the first input of the sixth key, the first output of which is connected through the inverter to the first input of the second adder, the output of which is connected to the input of the third amplifier, and the second output of the sixth key is connected to the second input of the second adder, the control input of the sixth key is designed to supply it with a signal from the first non-linear element, and the second non-linear element t is made in the form of an amplifier limiter.

Here "the error signal in speed is the result of the differentiation of the position error signal coming through the public key 18 at the input of the differentiation unit 9". However, the differentiation of the signal in the circuit leads to amplification of high-frequency noise (interference).

The disadvantages of the device are also not smooth regulation, but according to a “logical unit”, according to non-linear laws, which does not reduce the positioning errors of small angles and causes a large overshoot of the analog signal in amplitude and an increase in the process establishment time.

A large number of elements, such as two non-linear elements, the allocation of the module, two half-period rectifiers; complicate the claimed device and reduce its speed.

The task of the claimed control device for the robot arm is to increase speed, reduce positioning errors, simplify the device and expand the functionality.

The task is achieved in that the control device of the robot arm containing the comparison unit (adder), the first, second and third amplifiers, a rotation angle sensor connected to the first input of the comparison unit (adder) and an actuator, contains the fourth, fifth and sixth amplifiers, first and second integrators; the inputs of the first, second, and third amplifiers are connected to the output of the adder, the second inputs of which are connected to the angle sensor, and the first inputs are connected to the output of the first integrator, which is connected through the fifth amplifier to the first input of the second integrator, the second, third, fourth and fifth inputs which are associated with the outputs of the second, third, fourth and sixth amplifiers, respectively; the output of the second integrator is connected to the first input of the first integrator, as well as to the inputs of the fourth and sixth amplifiers, and the output of the first amplifier is connected to the second input of the first integrator, the first input of which is connected to the output of the first amplifier. The outputs of the fourth and fifth amplifiers are connected to the executive body.

The essence of the invention is represented by the following graphic materials:

Figure 1. Functional diagram of the proposed device

Figure 2. Transient without observing device and control by angular deviation (left) and angular velocity (right)

Figure 3. Transient with a monitoring device and control by angular deviation (left) and angular velocity (right)

Figure 4. Transient process of estimation of disturbing moment with observing device and control

On the diagram of the control device of the robot manipulator: 1 - rotation angle sensor, 2 - comparison unit (adder), 3, 4, 5, 6, 8, 9 - first, second, third, fourth, fifth and sixth amplifiers, 7, 10 - first and second integrators, 11 - executive body.

The inputs of the first 3, second 4, and third 5 amplifiers are connected to the output of the adder 1, the second inputs of which are connected to the angle sensor 1, and the first inputs are connected to the output of the first integrator 7, which is connected through the amplifier 8 to the first input of the second integrator 10, the second , the third, fourth and fifth inputs of which are connected with the outputs of the second 4, third 5, fourth 6 and sixth 9 amplifiers, respectively; the output of the second integrator 9 is connected to the first input of the first integrator 7, as well as to the inputs of the fourth 6 and sixth 9 amplifiers, and the output of the first amplifier 3 is connected to the second input of the first integrator 7, the first input of which is connected to the output of the first amplifier 3. The outputs of the fourth 6 and the fifth 8 amplifiers are connected to the executive body 11.

The device operates as follows. The signal of the angle sensor of the porosity 1 X _{1 is} compared (subtracted) with its estimate of X ₀₁ on the adder 2 and the difference signal is fed to the first, second and third amplifiers: 3, 4, 5, with amplification factors K ₁ , K ₂ , K ₃ , respectively . The amplified difference signals from the second 4 and third 5 amplifiers are fed to the summing second and third inputs of the integrator 10. The output signal of the integrator 10 X ₀₂ is an estimate of the angular velocity of the manipulator link, and this signal is fed to the inputs of the fourth 6 and sixth 9 amplifiers, as well as to the first input of the first integrator 7, which is integrated together with the signal from the first amplifier 3. The output of the first integrator the angular position estimate obtained X _01, which receives as input the adder (comparator) and at the fifth 8 ilitel signal from which the first input of the second integrator 10, the signals generated by the fourth and fifth 6 8 amps for adjusting the angular position and angular velocity of the manipulator unit are provided to the execution unit 11. The signal X at the output ₀₃ of the third amplifier 5 is integral evaluation disturbing moment.

 The advantage of the claimed device is the simplicity of its functional circuit and electrical components based on it. In automatic mode, the angular deviation is reduced, due to the disturbing moment and not allowing to accurately perform the specified movement of the manipulator link. The device has the ability in the current mode to record an estimate of the angular position at the output of the integrator 7, the angular velocity at the output of the second integrator 10, and from the output of the third amplifier 5, an integral estimate of the disturbing moment.

We give a theoretical justification for signal transformations in the claimed circuit.

The equation of motion of a link of a manipulator (Chernousko F.L., Bolotnik N.N., Gradetsky V.G.Manipulation robots: dynamics, control, optimization.- M.: Nauka. 1989. S.92 and p.286) has the form:

,(1)

,(one)

Where

- угол поворота звена манипулятора;

- the angle of rotation of the link of the manipulator;

- суммарный момент инерции звена манипулятора;

- total moment of inertia of the manipulator link;

- коэффициенты индуктивности и сопротивления электродвигателя;

- coefficients of inductance and resistance of the electric motor;

- коэффициент пропорциональности между током и электромагнитным моментом;

- proportionality coefficient between current and electromagnetic moment;

- управляющее напряжение.

- control voltage.

The manipulator is controlled in a given mode, as for the rotation of the link at large angles. At disturbing moments, small angular deviations remain uncompensated. The equation for the movement of the manipulator link with respect to the deviation of the parameters for an uncompensated disturbing moment M _{B can be} written as follows:

,(2)

, (2)

Using the method of observing devices (Kuzovkov N.T. Modal control and observing devices. M .: Mechanical Engineering. 1976. 184 p.), And denoting:

,

,

,

,

,

,

,

,

Here, the o index denotes the parameter estimate.

We get two systems of equations. We give them in the form of Cauchy. One of them describes its own motion without control under the action of a disturbing moment:

,(3)

, (3)

Another system of equations of motion of a link of a manipulator with an observing device and control:

,(4)

,(four)

,

- коэффициенты исполнительного механизма управления по углу и угловой скорости, соответственно;Where

,

- the coefficients of the actuator control angle and angular velocity, respectively;

,

,

-коэффициенты наблюдающего устройства.

,

,

-coefficients of the observing device.

These constant coefficients are calculated by equating the coefficients of the polynomial of the observing device with the coefficients of standard forms (for example, binomial) having a good dynamic characteristic.

The first two equations describe the dynamics of the real link of the manipulator under the action of a disturbing moment and a parry additive according to the estimate of the angle and angular velocity.

The third, fourth and fifth equation is an observing device with a regulator.

We present the results of modeling the equation with the following notation:

,

,

,

,

,

,

,

,

The results of modeling equations (3) - without an observing device and without control and equations (4) with an observing device and control, and by angle and angular velocity are shown in Fig. 2 and Fig. 3, respectively.

Evaluation of the disturbing moment specified in the second equation (4) M = 90 Rel. units, an observing device and control, is shown in Fig. 4.

The comparison showed a decrease in positioning error, i.e. amplitudes of the transient process according to the angle of rotation of the link of the manipulator by 4.5 times, by the angular velocity by 3 times, and the time of the steady-state process by 2 times when equipped with additional control and an observing device.

The circuit solution of the equation of algorithm (4) in the form of a functional diagram of Fig. 1., Performed, for example, on operational amplifiers, allows you to organize integrators (with a capacitor in feedback), amplifiers with amplification factors equal to the ratio of resistances in feedback and direct coupling, as well as adders and comparison elements when connecting a signal via direct or differential inputs, respectively.

The technical result of the claimed device consists in reducing the positioning error in the angle due to the formation of an estimate of the angular position and forcing it to be reduced due to appropriate adjustment in angle and angular velocity; in simplifying the functional diagram due to the absence of non-linear elements and keys, while the device diagram is made on two integrators, one adder and six amplifiers; in expanding the functionality by extracting from the circuit nodes in the current mode estimates of the angle, angular velocity and disturbing moment of the link for verification, adjustment or calibration.

Claims (1)

A robot manipulator control device comprising a comparison unit (adder), first, second and third amplifiers, a rotation angle sensor connected to the first input of the comparison unit (adder), and an actuator, characterized in that fourth, fifth, and sixth amplifiers are introduced into it , the first and second integrators, while the inputs of the first, second and third amplifiers are connected to the output of the adder, the second input of which is connected to the output of the first integrator, which is connected through the fifth amplifier to the first input of the second the second integrator, the second, third, fourth and fifth inputs of which are connected to the outputs of the second, third, fourth and sixth amplifiers, respectively, and the output of the second integrator is connected to the first input of the first integrator and to the inputs of the fourth and sixth amplifiers, while the output of the first amplifier is connected to the second input of the first integrator, and the outputs of the fourth and fifth amplifiers are connected to the executive body.

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