ES1322857U - Fruit picking manipulator - Google Patents

Abstract

The invention relates to manipulators with gripper heads for fruit harvesting. Such manipulator includes a base that carries an axially rotatable main beam, and an additional beam mounted on guides on the main beam and capable of moving along said guides parallel to the main beam when driven by an electric drive. The drive includes a lead screw and a nut mounted on an additional beam. The ends of the main and additional beams are equipped with fruit grippers. The fruit grippers carry electrodes of a high-frequency sensor for detecting fruit. The guides are installed so that the creation of a certain space between fruit grippers and the nearest guide becomes possible, whereas a spring is installed between the additional beam and said nut for controlling fruit compression ratio.

Description

DESCRIPTION

FRUIT HANDLER

Field of invention

The invention relates to agricultural equipment, specifically to manipulators with clamps for fruit harvesting.

Previous technique

Several designs of fruit picking manipulators are known.

Utility model patent CN203317431, published on December 4, 2013, IPC A01D46/30, discloses a manipulator design comprising a base, an electric drive, a lead screw, a parallelogram mechanism, and grippers. A pressure sensor is used to control the gripping force.

Utility model patent CN215968806, published 08-03-2022, IPC A01D46/30, describes the design of a fruit picking manipulator with drives including lead screws for moving two opposing clamping pieces.

Patent CN105922254, published on September 7, 2016, CIP B25J13/08, discloses the design of an electrically driven manipulator. Its electric motors rotate lead screws, while nuts installed on the grippers set the grippers in motion.

The previous design is the most similar to the case at hand.

Disclosure of the invention

The technical result achieved in the present invention is a lower probability of damage to the fruit when handling the manipulator without sacrificing the operational efficiency of the device.

A fruit-picking manipulator includes a base supporting an axially rotating main beam, as well as an additional beam mounted on guides fixed to the main beam. This additional beam is capable of moving along these guides parallel to the main beam under the action of an electric drive containing a lead screw and nut fixed to the additional beam. The ends of the main and additional beams are equipped with fruit grippers. The fruit grippers have electrodes for a high-frequency sensor to detect fruit. The guides are installed to create a certain gap between the fruit grippers and the nearest guide; furthermore, a spring is installed between the additional beam and the nut to control the fruit compression ratio.

Furthermore, the electric drive nut is fixed to the additional beam in such a way as to allow its displacement along the axis of the lead screw; the fruit compression ratio control spring is made in the form of a compression spring, and the additional beam is equipped with a nut displacement sensor.

Furthermore, an additional electric drive is installed at the base to allow axial rotation of the main beam up to 360°.

Also, the high-frequency fruit detection sensor has two contact electrodes, each mounted on a corresponding fruit clamp, these electrodes being connected to a high-frequency emitter and a fruit impedance measurement circuit, and they can be moved when they come into contact with a fruit.

Brief description of the drawings

Fig. 1 shows an overview of the fruit picking manipulator.

Fig. 2 shows a partial cross-section of the manipulator along the lead screw in its initial position.

Fig. 3 shows a partial cross-section of the manipulator along the feed screw when a fruit is inserted between the grippers.

Fig. 4 shows a side view of the manipulator.

Fig. 5 shows the manipulator in its initial position.

Fig. 6 shows the manipulator in the fruit-holding position.

Realizations of the invention

The manipulator (Fig. 1) includes a base 1 on which a main beam 2 is fixed. The main beam 2 contains guides 4, on which an auxiliary beam 3 is installed parallel to the main beam 2. An electric drive 5 in the form of an electric motor is mounted on the main beam 2 (Fig. 1 - Fig. 2). A threaded lead screw 6 and a nut 7 are attached to the lead screw. The nut 7, mounted on the auxiliary beam 3, is movable relative to the lead screw axis and rests on a support bar 14. The fruit compression ratio control spring is a compression spring 8 and is installed between the nut 7 and the auxiliary beam 3. In its initial position, the nut 7, together with the support bar 14, is pushed outward beyond the limits of the auxiliary beam 3 by the spring 8. This position of the nut 7 is recorded by the sensor 9. The sensor 9 detects the displacement of the nut 7. by a capacitive, optical, inductive, or Hall effect sensor. To protect the fruit 17 from excessive compression, an additional limiter 15 is used, which is mounted on the ends of the support bar 14 that protrude from the slots of the additional beam 3 and in the space between the main beam 2 and the additional beam 3.

The ends of the main beam 2 and the additional beam 3 are equipped with cup-shaped fruit clamps 10. The fruit clamps 10 house contact electrodes 12 of a high-frequency fruit detection sensor. The contact electrodes 12 are connected to a high-frequency emitter and a fruit impedance measurement circuit (not shown in the Figures) and are displaced upon contact with fruit 17. The high-frequency sensor detects the presence of fruit based on the measured impedance using ultra-high frequency signals (840–960 MHz). The impedance of fruit, for example, apples, measured at these frequencies differs significantly from that of tree branches or leaves, enabling reliable fruit detection. The electrodes 12 of the high-frequency sensor are able to move toward the clamps 10 upon contact with fruit 17.

The guides 4 located between the main beam 2 and the additional beam 3 can create a gap 11 between the fruit grippers 10 and the nearest guide 4. The presence of this gap 11 reduces the possibility of damaging the fruit 17 if the manipulator's guidance system makes an error in measuring the distance to the fruit. In this case, the fruit reaches the gap 11 and avoids damage from parts of the manipulator, such as guide 4.

A distinctive feature of the manipulator design is the ability of the main beam 2 to rotate axially with respect to the base 1 by means of an additional electric drive 13 and a rotation mechanism 16.

The system for guiding and orienting the manipulator toward the fruit is not considered in this embodiment and is not shown in the Figures. Such a system may be based on established principles using optical, ultrasonic, and other types of sensors.

The fruit picking manipulator operates as follows: The manipulator's guidance and orientation system leads it to fruit 17 (Fig. 5). The high-frequency sensor electrodes 12 touch a piece of fruit, and the fruit impedance measurement circuit determines that the fruit has been placed between the cup-shaped grippers 10. The manipulator's control system then activates the electric drive 5 and the auxiliary beam 3, which, due to the mechanical transmission of the feed screw 6 and nut 7, closes onto the main beam 2 (Fig. 3 - Fig. 6). The additional beam 3 begins to move under the pressure of the nut 7 transmitted via the compression spring 8. At that moment, the fruit is compressed by the grippers 10, resistance to movement arises, causing the additional beam 3 to stop, while the lead screw 6 continues to rotate the nut 7, thus compressing the spring 8 until contact is lost between the displacement sensor 9 and the nut 7. The electric drive 5 stops, and the fruit is gripped between the grippers 10 with sufficient force to avoid damaging the fruit 17. The stem of the fruit, for example, an apple, is detached as a result of the axial rotation of the main beam 2 at a predetermined angle of up to 360°, which is driven by the additional electric drive 13, in conjunction with the movement of the manipulator, for example, backward. Subsequently, the manipulator's grippers 10 are released in the fruit discharge zone.

Industrial applicability

A manipulator of this type is easy to manufacture, efficient, and provides gentle handling of the fruit at every stage of harvesting, from the moment the manipulator points at the fruit until the moment the fruit is unloaded from the manipulator.

Claims (4)

1. A fruit picking manipulator, comprising a base supporting an axially rotatable main beam, as well as an additional beam mounted on guides fixed to the main beam and capable of moving along said guides parallel to the main beam under the action of an electric drive containing a lead screw and nut fixed to the additional beam; whereas the ends of the main beam and the additional beam are equipped with fruit grippers, housing electrodes of a high-frequency sensor used to detect the fruit to be picked; furthermore, said guides are installed so as to create a space between the fruit grippers and the guide nearest them; furthermore, between the additional beam and said nut, a spring is installed to control the fruit compression ratio. 2. The manipulator according to claim 1, wherein the electric drive nut is fixed to the additional beam so as to allow its axial displacement along the lead screw; while the fruit compression ratio control spring is made in the form of a compression spring; furthermore, the additional beam is equipped with a sensor to detect the displacement of the nut. 3. The manipulator according to claim 1, wherein an additional electric drive is installed at the base to allow axial rotation of the main beam at an angle of up to 360°. 4. The manipulator according to claim 1, wherein the high-frequency fruit detection sensor comprises two contact electrodes, each of which is mounted on the corresponding fruit gripper and both are connected to a high-frequency emitter and a fruit impedance measurement circuit; furthermore, said electrodes are capable of moving upon contact with the fruit.