Patents by Inventor Lifu ZHANG

Lifu ZHANG has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10744643
    Abstract: The present disclosure provides a robot servo jitter suppression method and device. The method includes: counting an amount of reciprocating jitter of an angular position of an output shaft of a robot servo in a predetermined period, after the robot servo enters a lock position state for a first predetermined period; determining whether the robot servo is in a jitter state according to the amount of the reciprocating jitter of the angular position of the output shaft of the robot servo and a predetermined fluctuation value; and suppressing the jitter of the robot servo by adjusting control parameter(s) of the robot servo, in response to the robot servo being in the jitter state. The robot servo jitter suppression method and device solve the problem of the jitter of the robot servo appears when the virtual positions of the robot servo and the robot joint structure are not properly controlled.
    Type: Grant
    Filed: April 24, 2018
    Date of Patent: August 18, 2020
    Assignee: UBTECH ROBOTICS CORP
    Inventors: Youjun Xiong, Lifu Zhang, Wenhua Fan, Zhenmin Mo
  • Patent number: 10740873
    Abstract: Disclosed is an extraction method for time-space-spectrum four-dimensional remote sensing data. The method includes: obtaining remote sensing images at a preset coverage area during a preset time period (S1); re-projecting the remote sensing images in a way that the respective pixel positions of the respective remote sensing images at different time points are overlapped (S2); storing all of re-projected remote sensing images into a storage unit according to a first preset storage method, or storing all of the re-projected remote sensing images into the storage unit according to a second preset storage method (S3); determining, on the basis of requirement information for data extraction, whether current data format of remote sensing data is a data format matching the requirement information (S4); if yes, determining, on the basis of the requirement information, a storage location of required remote sensing data, and extracting the required remote sensing data (S5).
    Type: Grant
    Filed: April 1, 2016
    Date of Patent: August 11, 2020
    Assignee: INSTITUTE OF REMOTE SESING AND DIGITAL EARTH, CHINESE ACADEMY OF SCIENCES
    Inventors: Lifu Zhang, Xuejian Sun, Xia Zhang
  • Patent number: 10727821
    Abstract: The present disclosure provides a transmission hysteresis detecting method and apparatus. The method includes: transmitting a forward rotational instruction and a reverse rotational instruction to a motor of the servo; storing motor end positions of the motor and output shaft end positions of an output shaft corresponding to the motor in a forward rotational cycle and a reverse rotational cycle, respectively; generating first position data based on the motor end positions and the corresponding output shaft end positions in the forward rotational cycle; generating second position data based on the motor end positions and the corresponding output shaft end positions in the reverse rotational cycle; and calculating a transmission hysteresis of the servo based on the first position data and the second position data. The technical solutions of the present disclosure only needs to obtain the position data of one forward rotational cycle and one reverse rotational cycle.
    Type: Grant
    Filed: July 12, 2019
    Date of Patent: July 28, 2020
    Assignee: UBTECH ROBOTICS CORP LTD
    Inventors: Youjun Xiong, Lifu Zhang, Wenhua Fan, Hanyu Sun
  • Publication number: 20200206922
    Abstract: The present disclosure provides a robot joint motion control method and apparatus as well as a robot using the same. The method includes: obtaining coordinates of a plurality of key points of a motion of a joint of the robot based on a preset linear control model; determining coordinates of two smooth connecting points respectively before and after each key point based on a preset time connecting factor; calculating a joint motion trajectory between each two adjacent smooth connecting points using a preset parabola connecting formula, based on the coordinates of the two smooth connecting points and the corresponding key point; and controlling the joint of the robot to move according to the joint motion trajectory between each two adjacent smooth connecting points. The present disclosure can avoid the joints of a robot from overshooting, thereby enhancing the user experience.
    Type: Application
    Filed: December 30, 2018
    Publication date: July 2, 2020
    Inventors: YOUJUN XIONG, Jianxin Pang, Lifu Zhang, Wenhua Fan, Dong Liu
  • Publication number: 20200206929
    Abstract: The present disclosure provides duplicate servo ID detection methods and a servo for a robot. One of the method includes: transmitting, by the main controller, a query instruction including a specific servo ID to at least two of the servos of the robot through a bus; differentiating feedback information replied by at least two of the servos corresponding to the specific servo ID; and determining, by the main controller, there being at least two of the servos with the same servo ID, if the feedback information not meeting a predetermined verification rule is received. Through the technical solution provided by this embodiment, the detection of duplicate servo ID can be realized, and the servos on the bus that have the same servo ID can be found so us to remind the user of the robot, thereby guaranteeing the normal operation of the robot.
    Type: Application
    Filed: December 27, 2019
    Publication date: July 2, 2020
    Inventors: Youjun XIONG, Hanyu Sun, Lifu Zhang, Wenhua Fan, Zhongliang Wang, Jianxin Pang
  • Publication number: 20200206936
    Abstract: The present disclosure provides a servo output shaft angle calibration method and a robot using the same. In the method, when a servo output shaft rotational angle calibration instruction is obtained, an output shaft of a servo is controlled to move in a preset rotational direction, a current angle of the output shaft of the servo is obtained when it detects that the output shaft of the servo has rotated to an end point and has a stalling, and then a preset end point angle is updated as the current angle of the output shaft of the servo, so as to take the current angle of the output shaft of the servo as the new end point angle, thereby realizing the calibration of the end point angle of the output shaft of the servo. In this manner, the entire calibration process requires no manual intervention.
    Type: Application
    Filed: August 8, 2019
    Publication date: July 2, 2020
    Inventors: YOUJUN XIONG, Hanyu Sun, Lifu Zhang, Wenhua Fan, Zhongliang Wang, Yongping Zeng, Jianxin Pang
  • Publication number: 20200206935
    Abstract: The present disclosure provides a servo calibration method as well as an apparatus and a robot using the same. The method includes: obtaining data of a position sensor on a motor shaft of the servo; obtaining data of a position sensor on an output shaft of the servo; determining whether a clutch protection has been performed on the servo based on data of the position sensor on the motor shaft and data of the position sensor on the output shaft; and calibrating a position of the motor shaft based on the data of the position sensor on the output shaft, if the clutch protection has been performed on the servo. Through the present disclosure, the problem in the prior art that the process of the calibration is cumbersome can be solved.
    Type: Application
    Filed: July 11, 2019
    Publication date: July 2, 2020
    Inventors: YOUJUN XIONG, Hanyu Sun, Wenhua Fan, Lifu Zhang, Zhongliang Wang, Jianxin Pang
  • Publication number: 20200212897
    Abstract: The present disclosure provides a transmission hysteresis detecting method and apparatus. The method includes: transmitting a forward rotational instruction and a reverse rotational instruction to a motor of the servo; storing motor end positions of the motor and output shaft end positions of an output shaft corresponding to the motor in a forward rotational cycle and a reverse rotational cycle, respectively; generating first position data based on the motor end positions and the corresponding output shaft end positions in the forward rotational cycle; generating second position data based on the motor end positions and the corresponding output shaft end positions in the reverse rotational cycle; and calculating a transmission hysteresis of the servo based on the first position data and the second position data. The technical solutions of the present disclosure only needs to obtain the position data of one forward rotational cycle and one reverse rotational cycle.
    Type: Application
    Filed: July 12, 2019
    Publication date: July 2, 2020
    Inventors: Youjun Xiong, Lifu Zhang, Wenhua Fan, Hanyu Sun
  • Patent number: 10685672
    Abstract: The present disclosure provides a linearity detecting method and apparatus for a servo position sensor, and a robot with the same. The method includes: collecting and saving an output angle of the servo under test; analyzing the output angle to obtain a relationship curve of angle and time of the servo under test to rotate for one turn; extracting angle information of a starting point to an ending point of the output angle corresponding to the position sensor in the servo under test based on the relationship curve of angle and time to obtain valid angle data; and determining whether the output angle corresponding to the position sensor is linear based on the valid angle data. The present disclosure can solve the problem that an external sensor and a fixture are required when detecting the linearity of the sensor which causes complicated operation, high detection cost, and low detection efficiency.
    Type: Grant
    Filed: October 18, 2018
    Date of Patent: June 16, 2020
    Assignee: UBTECH ROBOTICS CORP
    Inventors: Youjun Xiong, Lifu Zhang, Wenhua Fan, Malin Wang
  • Publication number: 20200164511
    Abstract: The present disclosure provides a servo motion control method and apparatus, as well as a robot using the same. The method includes: obtaining position parameters of a plurality of control vertices of a servo in a constant speed motion; creating a first smooth trajectory equation of the servo to move from the starting point to the ending point based on the position parameters of the plurality of control vertices; and controlling the servo to move based on the first smooth trajectory equation. The present disclosure is capable of realizing the smooth control of the motion of the servo from a starting position to an ending position, and avoiding the severe impacts during starting and stopping which affect the stability of the servo while the servo is in a constant high-speed motion.
    Type: Application
    Filed: December 30, 2018
    Publication date: May 28, 2020
    Inventors: Youjun Xiong, Lifu Zhang, Hanyu Sun, Xi Bai, Jianxin Pang
  • Publication number: 20200137295
    Abstract: A method for controlling image capture includes receiving, from a movable device, an image of a target imaging area; adjusting, by a first control apparatus and a second control apparatus, one or more imaging parameters for imaging the target imaging area based at least in part on the image to obtain one or more adjusted imaging parameters; and sending, by the first control apparatus and/or the second control apparatus, an instruction carrying the one or more adjusted imaging parameters to the movable device.
    Type: Application
    Filed: January 30, 2018
    Publication date: April 30, 2020
    Inventors: Heli ZHONG, Bingzhen YANG, Lifu YU, Zhiyuan ZHANG
  • Patent number: 10627805
    Abstract: The present disclosure relates to servo control technology, which provides a method, device, and terminal device for servo movement smoothing. The method includes: obtaining a starting position and a control command for a rotation of an output shaft the servo; determining an ending position and a rotation time for the rotation of the output shaft in accordance with the control command; constructing a movement curve of the output shaft based on the starting position, the ending position, and the rotation time; and controlling the output shaft to rotate from the starting position to the ending position in accordance with the movement curve. The above-mentioned method smooths the movement of the servo by constructing a simple linear function, which greatly reduces the calculation amount in comparison with the technical solution using the cubic Bessel formula, and is capable of reducing the requirements for the hardware performance of servos.
    Type: Grant
    Filed: September 25, 2018
    Date of Patent: April 21, 2020
    Assignee: UBTECH ROBOTICS CORP
    Inventors: Youjun Xiong, Lifu Zhang, Dong Liu, Hanyu Sun
  • Patent number: 10564631
    Abstract: A servo movement control method, device, and terminal device are provided. The method includes: controlling an output shaft of the servo to rotate according to a first motion instruction; detecting whether a second motion instruction is received within a first preset time period, and re-planning a second target motion curve to a second target end position from a corresponding target position on a first target motion curve when receiving the second motion instruction; and controlling the output shaft to rotate from an actual position when receiving the second motion instruction to the second target end position according to the second target motion curve. When the second motion instruction is received, the servo is controlled to rotate from the target position to the second target end position according to the second motion instruction, so that the servo is switched from the first motion instruction to the second motion instruction smoothly.
    Type: Grant
    Filed: September 25, 2018
    Date of Patent: February 18, 2020
    Assignee: UBTECH ROBOTICS CORP
    Inventors: Youjun Xiong, Lifu Zhang, Mingzhao Li, Zhenmin Mo
  • Patent number: 10488298
    Abstract: The present disclosure is an apparatus for testing an idle position of a servo, including: driving mechanism, a transmission unit transmitting torque of a driving servo to a testing servo, and a control circuit electrically connecting to the driving servo and the testing servo to acquire idle position information. The apparatus drives the output shaft of the testing servo to rotate by an external driving mechanism, and measures an amount of rotation of the output shaft by an internal sensor of the testing servo. Therefore, an external sensor may not be provided, and a problem of precision installation of the external sensor can be avoided. Further, a problem caused by poorly install the external sensor and the output shaft can also be avoided, and accuracy of a testing result can be increased.
    Type: Grant
    Filed: July 4, 2017
    Date of Patent: November 26, 2019
    Assignee: UBTECH ROBOTICS CORP.
    Inventors: Hongbo Zhu, Lifu Zhang, Youjun Xiong
  • Patent number: 10451647
    Abstract: A method for measuring speed of a permanent magnet synchronous motor includes: acquiring a number K of pulse signals received in a current measuring period and outputted by an incremental encoder; acquiring a first duration Sn-1 between a time point when a pulse is last received in a previous measuring period and a time point when the previous measuring period ends, and a second duration Sn between a time point when a pulse is last received in the current measuring period and a time point when the current measuring period ends; calculating a third duration T0, measured between the time point when the pulse is last received in the previous measuring period and the time point when the pulse is last received in the current measuring period, according to the length T of the current, measuring period, the first duration Sn-1 and the second duration Sn; and calculating a motor speed v according to formula: v = K K 0 × 1 T ? ? 0 .
    Type: Grant
    Filed: March 9, 2017
    Date of Patent: October 22, 2019
    Assignee: UBTECH Robotics Corp.
    Inventors: Youjun Xiong, Wenhua Fan, Lifu Zhang, Jianyun Xiao
  • Patent number: 10379510
    Abstract: The present disclosure discloses a command control in a multi-servo feedback control system. The command control includes: a servo acquiring preset delay time when a first action command is received from a main controller via serial data bus; the servo sending feedback information to the main controller after the preset delay time; wherein the preset delay time of the plurality of servos are different from each other, and the feedback information is configured to identify work status of the servo; receiving a second action command from the main controller; performing actions corresponding to the second action command and sending the feedback information to the main controller after the preset delay time if the second action command is valid. A servo and a multi-servo feedback control system for performing the command control are also provided.
    Type: Grant
    Filed: December 30, 2016
    Date of Patent: August 13, 2019
    Assignee: UBTECH Robotics Corp.
    Inventors: Tingshuang Huang, Lifu Zhang, Youjun Xiong
  • Publication number: 20190198048
    Abstract: The present disclosure provides a linearity detecting method and apparatus for a servo position sensor, and a robot with the same. The method includes: collecting and saving m output angle of the servo under test; analyzing the output angle to obtain a relationship curve of angle and time of the servo under test to rotate for one turn; extracting angle information of a starting point to an ending point of the output angle corresponding to the position sensor in the servo under test based on the relationship curve of angle and time to obtain valid angle data; and determining whether the output angle corresponding to the position sensor is linear based on the valid angle data. The present disclosure can solve the problem that an external sensor and a fixture are required when detecting the linearity of the sensor which causes complicated operation, high detection cost, and low detection efficiency.
    Type: Application
    Filed: October 18, 2018
    Publication date: June 27, 2019
    Inventors: Youjun Xiong, Lifu Zhang, Wenhua Fan, Malin Wang
  • Publication number: 20190196453
    Abstract: The present disclosure relates to servo control technology, which provides a method, device, and terminal device for servo movement smoothing. The method includes: obtaining a starting position and a control command for a rotation of an output shaft the servo; determining an ending position and a rotation time for the rotation of the output shaft in accordance with the control command; constructing a movement curve of the output shaft based on the starting position, the ending position, and the rotation time; and controlling the output shaft to rotate from the starting position to the ending position in accordance with the movement curve. The above-mentioned method smooths the movement of the servo by constructing a simple linear function, which greatly reduces the calculation amount in comparison with the technical solution using the cubic Bessel formula, and is capable of reducing the requirements for the hardware performance of servos.
    Type: Application
    Filed: September 25, 2018
    Publication date: June 27, 2019
    Inventors: Youjun Xiong, Lifu Zhang, Dong Liu, Hanyu Sun
  • Patent number: 10317874
    Abstract: The present disclosure relates to a critical point locking method of servos, including: computing a current target deviation according to a target position and an actual position, computing a variation value according to the current target deviation and a previous target deviation, determining whether the variation value being greater than a constraint value, modifying the current target deviation according to the current target deviation and a predetermined value upon determining the predetermined condition being satisfied, configuring the modified current target deviation as a current controlling deviation, and driving the servo to move toward the target position according the current controlling deviation. As such, the servo may lock the position for 360 degrees, the locking stroke of the servo may be improved, and the application of the servo may be enlarged.
    Type: Grant
    Filed: July 3, 2017
    Date of Patent: June 11, 2019
    Assignee: UBTECH Robotics Corp.
    Inventors: Youjun Xiong, Lifu Zhang, Xi Bai, Wenhua Fan
  • Publication number: 20190160669
    Abstract: The present disclosure provides a robot servo jitter suppression method and device. The method includes: counting an amount of reciprocating jitter of an angular position of an output shaft of a robot servo in a predetermined period, after the robot servo enters a lock position state for a first predetermined period; determining whether the robot servo is in a jitter state according to the amount of the reciprocating jitter of the angular position of the output shaft of the robot servo and a predetermined fluctuation value; and suppressing the jitter of the robot servo by adjusting control parameter(s) of the robot servo, in response to the robot servo being in the jitter state. The robot servo jitter suppression method and device solve the problem of the jitter of the robot servo appears when the virtual positions of the robot servo and the robot joint structure are not properly controlled.
    Type: Application
    Filed: April 24, 2018
    Publication date: May 30, 2019
    Inventors: Youjun Xiong, Lifu Zhang, Wenhua Fan, Zhenmin Mo