# Continuum Manipulator Rover Picking Tomatoes

How a six\-wheeled field rover rolls over bumpy soil and uses a bendy, elbowless arm to pick ripe red tomatoes\.

By Vipin Pachouri

Topic: Engineering

[Open the interactive Jig](https://ask.jig.com/j/AJ4pyzH5cDzC)

## Transcript

### 1. A 5\-second tomato pick

Watch a six\-wheeled field rover roll over bumpy soil, stop by a tomato plant and pick a ripe red tomato with its bendy arm\. The whole pick plays in five seconds\.

This film is sped up\. Real picking robots take about a minute per tomato\.

### 2. Six wheels that follow the ground

Each side has a long link called a rocker and a shorter one called a bogie\. They swing on pins, so all six wheels stay on the ground as the rover climbs lumps and dips\.

The same rocker\-bogie design carries NASA's Mars rovers\. It uses pivots, not springs\.

### 3. A see\-saw keeps the body level

A bar across the top joins the left and right rockers like a see\-saw\. When one side climbs, the bar tips and the body sits halfway between, so the crate barely tilts\.

A rocker\-bogie rover can roll over a bump about as tall as one of its wheels\.

### 4. Spotting the ripe ones

A camera on the mast looks along the row\. Tomatoes ripen from green to orange to red, and the rover only picks fruit that is almost completely red\.

Unripe green fruit stays on the plant for another day\.

### 5. An arm with no elbows

A continuum arm bends smoothly along its whole length, like an elephant's trunk\. Motors pull thin cables through a stack of discs, curling each half of the arm into a gentle arc\.

With two halves it can make an S\-shape to reach around leaves\.

### 6. A gentle grip and a twist

Three soft fingers close around the tomato without squeezing hard\. A small twist snaps the stalk, and the arm carries the fruit back to the crate\.

Tomato skin bruises easily, so the grip is soft and limited\.

### 7. Slow, steady and tireless

Robots like this are still slower than people, but they can work long days on rough ground\. Press the button to pick the next ripe tomato\.

Each tomato is about 6 cm across, a little bigger than a golf ball\.