SU1230480A1 - Self-adjusting device for automatic guiding of tractor movement - Google Patents

Description

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The invention relates to agriculture, in particular to the road transport of agricultural aggregates,

The purpose of the invention is to simplify the device's construction.

The drawing shows the structure of the scheme for one side of the tractor (for the other. The border is similar),

The device consists of a circuit of 1 control, a circuit 2 of self-tuning of an additional circuit 3 of control.

The control circuit consists of a sensing element 4, a sensor 5, a pulse element 6, a delay element 7, a servo drive 8 and a control object 9.

The delay link 7 is made to a time relay, which secures the end of the output signal of the pulse element 6 without changing the beginning of the arrival of this signal on the servo drive 8.

The self-tuning contour 2 consists of a pulse element 10, an analyzer P and an actuating element 12,

The additional control circuit 3 consists of a delay link 13 and an additional servo 14 connected to the control object 9.

The delay link I3 is made in the form of a time relay providing a delay in the start of the control signal of the pulse element 6 without changing the moment of its end at the output of the delay link 13.

The setting of the delay time of the signal of the pulse element 6 by the delay links 7 and 13 is made during the manufacture of the device and can be adjusted by the operator if necessary (preventive settings).

The length of the delay time of the delay link 7 is determined by the return time to the initial position of the additional servo 14. The delay time of the signal of the delay link 13 is set depending on the characteristics of the control object 9 and for modern tracked tractors can be adopted in the range of 0.1-0.35 c, depending on the time of complete movement of the additional servo 14.

Servomotors 8 and i 4 are made in the form of hydro-electrosolding devices and hydraulic cylinders. Hydraulic cylinder230480 ry

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associated with the mechanisms of tractor rotation in such a way that the servo drive 8 acts on the planetary brake (friction clutch), and the additional servo drive 14 acts on the stopping brake of the turning mechanism. Servos 8 and 14 can be made in the form of other actuators, such as electric drives, pneumatic actuators, etc,

The elements 4-9 of the control circuit 1 are connected in series with the feedback of the object to the input of the sensitive element 4. The input of the pulse element 10 of the self-tuning circuit 2 is connected to one of the outputs of the pulse element 6 of the control circuit 1, and its output is connected to the analyzer. The other input of the analyzer 1 is connected to the output of the sensitive element 4, and its output is connected to the input of the actuating element 12, the output of which is connected to the input of the trimmer of the pulse element 6 of the control circuit 1. The input of the delay element 13 of the additional control circuit 3 is connected to the output of the pulse element 6 of the main control loop 1, and the output of the delay link 13 is connected to the input of the servo drive 14 of the additional control circuit, the output of which is connected to another input of the control object 9.

The sensing element 4 is made in the form of a mechanical copier or any other device that records the deviations of the object from the desired position. Sensor 5 performs the role of an actuating element and has a two-position characteristic. Here, one control of the e.-1st tractor side is considered, while simultaneously examining the diagrams of two controllable boards, the characteristic of sensor 5 is transformed into a three-position one with a dead zone. The pulse element 6 converts the signal of the sensor 5 into a pulse signal. The delay link 7 transmits the pulse signal of the element 6 without changing the beginning of the pulse and delays it

permanent ending L

about

Thus, the duration of the control signal coming to ser0

five

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WITH

five

actuator

is equal to Lg (+ LT, where

the duration of the control pulse of element 6; t, the delay time of the link 7, Servo 8 is used

control mechanism, it acts on the input of the control object 9.

The pulse element 10 of the self-tuning circuit 2 is connected to another output of the pulse element biv. The moment the pause ends of the element 6 generates a pulse signal of constant duration. Analyzer 11 is a three position device. Actuator 12 is reversible. a stepper motor or any other device providing the corresponding characteristic, and an example of a computing device determining the pulse duration of element 6 in accordance with the formula

V-

where we are - constant 1te-20

The time period that determines the tuning step; n is the number of signals from analyzer 11 to element 12 with a positive sign; ha - the number of signals from the analyzer 11 to the element 12 with a negative sign. The Executive unit 12 is connected to a trimmer (not shown) of the pulse element 6.

The input of the delay link of the additional control circuit 3 is connected to the output of the pulse element 6. The delay link 13 delays the beginning of the passage of the pulse signal of the element 6 for a constant time. Thus, the duration of the control pulse signal fed to the auxiliary servo drive 14 is determined by the expression t -

The end delay of the pulse signal of element 6 in circuit 1 of control of delay link 7 and the delay of the pulse signal start of passage of element 6 of delay link I3 provides the required sequence of operation of servo drives 8 and 14. First, the servo drive 8 is turned on, then, if the duration t, the servo becomes longer 14. At the moment

Yu (

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The control pulse action ocoichap at first open: yn .; servo 4 and then servo 8.

The proposed device works as follows.

At a normal speed of tractor rotation, for example, when the hook force is sufficiently large, the system works as if it is self-tuning (because V is small and less than G, so the servo 4 signal passes through the servo or its duration is insufficient and the servo's response is 14. thus, the additional control circuit 3 remains disconnected.

As y increases the rotational speed of the tractor, for example, by decreasing the hook or increasing the moment of resistance to turning the tractor, the pulse duration increases, and element 6 increases due to the self-tuning circuit 2. When its value increases to such an extent that the pulse duration of the element 6 becomes longer than the delay time t,., Of the delay link 13, an additional servo drive 14 is put into operation, which begins to act on the stopping brake (other input) of the object, increasing the angular speed of the tractor turn. The tractor starts to be controlled by control circuit 1 and additional control circuit 3.

When the additional circuit 3 is in operation, it is necessary to turn on the turn-on sequence (first, the servo drive 8, and then 14) and the turn-off sequence (first, the servo drive 14, and then the servo drive 8, control loop 1). This is achieved by setting the required delay time T and 1 delay unit 7 and 13.

Thus, the device provides operating modes based on the principle of variable structure. At the same time, the design of the device and its manufacturing technology are considerably simplified in comparison with the prototype.

Claims (1)

SELF-ADJUSTING DEVICE FOR AUTOMATIC DIRECTION OF TRACTOR MOTION, containing for each side similarly made control loop, which includes a sensitive element, sensor, pulse element connected in sequence, and a servo drive connected to the control object, a self-tuning circuit, which includes the second pulse element, actuator, which includes the second pulse element, and an analyzer, the first input of which is connected to the output of the sensing element, the second input - with the output of the second pulse element, and the output - with the input of - an additional mechanism, the output of which is connected to the second input of the pulse element, and an additional control circuit, which includes an additional servo drive associated with the control object, characterized in that, in order to simplify the design of the device and its manufacturing technology, into the control circuit between the pulse element and a servo-drive, the first delay link is sequentially connected to provide an increase in the duration of the control pulse of the pulse element during its termination, in an additional circuit between the SSs between the pulse element and the additional servo drive, a second delay link is connected in series to provide a reduction in the duration of the control pulse of the pulse element, in addition, the second output of the pulse element of the control loop is connected to the input of the second pulse element. SU ... 1230480 A1 ί