Intelligent Picking (Customization)

Success Sample: Overall solution for Cardamom dual-arm robot

A. Description of basic structural design 

Overall structure of the machine

Track chassis module

The chassis supports the weight of the entire machine and facilitates its movement and steering through the tracks. The tracked chassis primarily consists of components such as the track frame, the four-wheel-one-belt (support wheels, drive wheels, guide wheels, carrier rollers, and tracks), tensioning devices, mounting bolts, and mounting brackets.

Lifting electric cylinder module

The electric lifting cylinder, driven by a servo motor, performs linear up-and-down movements. It incorporates a self-locking mechanism, ensuring that the cylinder remains stationary even in the event of a sudden power loss during operation. This prevents potential damage from falling.

Six-axis robotic arm module

The position of the flexible gripper module can be adjusted. Compared to other robotic arms, the six-axis is more flexible and more suitable for complex working conditions.

Flexible gripper module

Grasp the branches of cardamom tightly to ensure stability and accuracy for the harvesting operation. And because of the flexible material, the clamping jaw will not damage the branches during the clamping process.

Fruit suction module

The harvested cardamoms are transported to the storage module by suction through a blower and a pipeline. This saves harvesting time and improves efficiency.

Structural design of pressure detection gripper

Due to varying requirements for fruit hardness in cardamom harvesting, different sales methods necessitate the harvesting of fruits of different hardness levels. To fulfill this harvesting requirement, a flexible gripper equipped with a force sensor is employed. Specifically, the harvesting range (softness and hardness) is set according to different needs. The moment the gripper grips the fruit, it senses the softness and hardness of the fruit. Based on the preset parameters, it determines whether the fruit meets the harvesting criteria. If the softness and hardness exceed the harvesting range, the gripper will release and abandon the harvesting. Otherwise, normal harvesting will proceed. As shown in Figure 8, the maximum radius range of the cardamom is located, and then the flexible gripper grips the corresponding position. With the same stroke, the deformation of the gripper serves as the basis for determining the softness and hardness levels.

The gripper is divided into two layers: the upper and lower layers. During harvesting, the lower layer encloses the fruit and determines its softness through changes in travel distance and force sensing, serving as an indicator for judging ripeness. Once judged to be ripe, the upper layer gripper clamps the fruit stem, allowing the fruit to be harvested.

B.Picking process

1. Identify the end of the branch, grasp the end and straighten it, and the sensor determines whether it is straightened. After straightening, proceed with harvesting.
2. Identify the branches along their direction to the root, and start identifying the cardamom from the root.
3. Visual camera identifies the position of cardamom.
4. Adjust the position of the lifting module and the six-axis robotic arm module.
5. The flexible gripper module grips the cardamom and judges its softness or hardness.
6. If the fruits meet the picking standards, they will be adsorbed to the negative pressure shut-off device after being picked and transported to the picking box.
   

Our Testing Farm in Chengdu,China

Among them are various types of harvesting machines and agricultural intelligent robots for weeding, spraying pesticides, and fertilizing. They are integrated into smart farms and the construction of fully automated farms.

In the planned area of 20,000 square meters, various types of harvesting machines are planned to be planted in the demonstration area, including a demonstration scene of cardamom covering an area of 8 square meters.