Last-modified: 2012-08-23 (木) 15:00:00

Intelligent robot system

Tactile sensor on Fingers

High-speed handling

A tactile feedback system in real time using a high-speed multifingered robot hand and high-speed tactile sensor. The system is respectively capable of high-speed finger motion up to 180 deg per 0.1 s and high-speed tactile feedback with a sampling rate higher than 1 kHz.(Ishikawa-Lab in Tokyo Univ.)

• Ishihara T., Namiki A., Ishikawa M., Shimojo M., Dynamic pen spinning using a high-speed multifingered hand with high-speed tactile sensor 2006 6th IEEE-RAS International Conference on Humanoid Robots, 2006.

Contact detection

By the tactile sensor mounted in the finger, A collision is detected and a finger motion is stopped quickly.

Stanford JPL hand

Next video shows Stanford JPL hand with CoP sensor handling a piece of rod. The white part is sensor. The oscilloscope in the back shows the locus of a contact position on the fingertip. The horizontal axis shows the direction of the finger circumference, and a vertical axis shows the direction of the finger lengthwise.

Four finger robot hand

A new type of tactile sensor using pressure-conductive rubber with stitched electrical wires The following video is the grasping experiment by 4 finger robot hand.

Tactile sensors on manipulator

The tactile sensor mounted on a manipulator. When load is added to the sensor, the sensor detects the contact position and load and a robot arm will move in the direction of applied force.

Proximity sensor

The following shows the example of operation. Sensors are mounted on the top and the side of the manipulator. The sensor at the top tracks a white ball,and the sensor at the side avoid the white ball when it approaches. When an appearance of man is detected while tracking a white ball, a manipulator will carry out avoiding action.

Explanation in English(Net-shaped proximity sensor : DigInfo)

Proximity sensors on finger's tip

Proximity sensor array is mounted on each finger's tips. By using the sensor, An object surface and the fingertip surface are arranged in parallel. Then reliable grasping is carried out.

Proximity sensors on palm

Objects detection and grasping by the proximity sensor array attached on the palm. Objects detection is carried out without vision.

Proximity sensors on finger's tip & palm

By using proximity sensor on palm, hand is arranged right above an object. By using proximity sensor on fingers, fingertips are arranged at right angles to the object surface.

Moving Object Tracking Using Proximity Sensing

• H. Hasegawa, Y. Suzuki, A. Ming, M. Ishikawa, M. Shimojo, Robot Hand Whose Fingertip Covered with Net-Spaped Proximity Sensor /-Moving Object Tracking Using Proximity Sensing-, J. of Robotics and Mechatronics, vol.23, no.3,pp.328-337,2011

Integrating proximity, tactile and slip senses

Through integrating proximity, tactile and slip senses, detection from approach to contact was seamlessly carried out, and an intelligent robot hand that could reliably grasp/seize was proposed. Pick & Place was adopted as a practical task using the hand, and was successful in implementation under the conditions of 1) weight/shape/friction conditions are unknown and 2) placement error exists.

• Hasegawa, H.; Mizoguchi, Y.; Tadakuma, K.; Aiguo Ming; Ishikawa, M.; Shimojo, M.; Development of intelligent robot hand using proximity, contact and slip sensing， Robotics and Automation (ICRA), 2010 IEEE International Conference on,pp. 777 - 784,2010.

Omni-Directional Mobile robot

Intelligent omni-directional moblile robot "i-Carrier" is developed with the aim of the porter robot which is able to support load carriage safely in a crowded place such as an airport, a factory, etc.

Proximity sensor for recognizing an object in 360 degrees all around with response time only l[ms]. The sensor is especially available for avoiding sudden contact with rapidly approaching objects for mobile robots and other robotic systems. This model is designed for implementing on a mobile robot. The diameter of the sensor is 600[mm], and the height is 300[mm]. The number of elements is 60 in the circumferential direction and 3 in the height direction.~ When approaching objects are more than one, the sensor become scanning mode and then sensor outputs the direction of approach objects, distance, and a number.

The environmental map is used for movement to the destination. To the obstacle which is moving, avoiding action is carried out using a proximity sensor.

• Terada, K.; Suzuki, Y.; Hasegawa, H.; Sone, S.; Ming, A.; Ishikawa, M.; Shimojo, M.. Development of Omni-directional and Fast-responsive Net-structure Proximity Sensor, 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2011) pp. 1954-1961, 2011

Slip sensor

The object was held by fingers. The slip sensors output was fed back to the hand, and the grip force was adjusted in proportion to the weight of the object.

• Teshigawara, S.; Tadakuma, K.; Aiguo Ming; Ishikawa, M.; Shimojo, M.,High Sensitivity Initial Slip Sensor for Dexterous Grasp,2010 IEEE International Conference on Robotics and Automation (ICRA 2010),pp.4867-4872,2010

install slip sensor on robot hand

In this experiment, we performed the following two operations. Step 1: After an empty glass is gripped with minimal force, small particles are pour into the glass and the weight is increased. The slip sensor reacts when the object seems to slip, and the grip force is strengthened. Step 2: The hand decreases the gripping force, and when the slip sensor detects the initial slip of the glass, the hand strengthens the gripping force slightly. By repeating this operation, the hand can hold the object while applying minimal force. The control algorithm is simple. The gripping force is strengthened depending on the output from the slip sensor.

In video, Oscilloscope shows gripping force and lighting green lamp shows occurrence of slip.

• Teshigawara, S.; Tsutsumi, T.; Shimizu, S.; Suzuki, Y.; Ming, A.; Ishikawa, M.; Shimojo, M., Highly Sensitive Sensor for Detection of Initial Slip and Its Application in a Multi-fingered Robot Hand, 2011 IEEE International Conference on Robotics and Automation pp.1097-102, 2011..

Grasping force control based on slip detection

we propose a method for detecting the slip of a grasped object using the force output of Center of Pressure (CoP) tactile sensors. CoP sensors can measure the center position of a distributed load and the total load applied on the surface of the sensor, within 1ms.
In video, Oscilloscope shows gripping force

• Gunji, D.; Mizoguchi, Y.; Teshigawara, S.; Aiguo Ming; Namiki, A.; Ishikawaand, M.; Shimojo, M.,Grasping force control of multi-fingered robot hand based on slip detection using tactile sensor, 2008 IEEE International Conference on Robotics and Automation. Pages: 2605-10,2008.

Sensor Glove

Video shows a Sensor Glove for measurement of grasping force distribution. Sixteen sheets of sensor are sewn on the glove.

• S. SHIMIZU, M. SHIMOJO, S. SATO, K. SEKI, A. TAKAHASHI, Y. INUKAI and M. YOSHIOKA: The Relationship between force distribution patterns and grip types in human grasping motions, 8th International Conference on Advanced Robotics, Monterey, pp.299-304 (1997)