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).
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Patent number: 10564631Abstract: 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: GrantFiled: September 25, 2018Date of Patent: February 18, 2020Assignee: UBTECH ROBOTICS CORPInventors: Youjun Xiong, Lifu Zhang, Mingzhao Li, Zhenmin Mo
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Patent number: 10488298Abstract: 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: GrantFiled: July 4, 2017Date of Patent: November 26, 2019Assignee: UBTECH ROBOTICS CORP.Inventors: Hongbo Zhu, Lifu Zhang, Youjun Xiong
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Patent number: 10451647Abstract: 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: GrantFiled: March 9, 2017Date of Patent: October 22, 2019Assignee: UBTECH Robotics Corp.Inventors: Youjun Xiong, Wenhua Fan, Lifu Zhang, Jianyun Xiao
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Patent number: 10379510Abstract: 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: GrantFiled: December 30, 2016Date of Patent: August 13, 2019Assignee: UBTECH Robotics Corp.Inventors: Tingshuang Huang, Lifu Zhang, Youjun Xiong
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Publication number: 20190198048Abstract: 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: ApplicationFiled: October 18, 2018Publication date: June 27, 2019Inventors: Youjun Xiong, Lifu Zhang, Wenhua Fan, Malin Wang
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Publication number: 20190196453Abstract: 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: ApplicationFiled: September 25, 2018Publication date: June 27, 2019Inventors: Youjun Xiong, Lifu Zhang, Dong Liu, Hanyu Sun
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Patent number: 10317874Abstract: 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: GrantFiled: July 3, 2017Date of Patent: June 11, 2019Assignee: UBTECH Robotics Corp.Inventors: Youjun Xiong, Lifu Zhang, Xi Bai, Wenhua Fan
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Publication number: 20190160669Abstract: 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: ApplicationFiled: April 24, 2018Publication date: May 30, 2019Inventors: Youjun Xiong, Lifu Zhang, Wenhua Fan, Zhenmin Mo
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Publication number: 20190121328Abstract: 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 ideal motion curve to a second ideal end position from a corresponding ideal position on a first ideal 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 ideal end position according to the second ideal motion curve. When the second motion instruction is received, the servo is controlled to rotate from the ideal position to the second ideal 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: ApplicationFiled: September 25, 2018Publication date: April 25, 2019Inventors: Youjun Xiong, Lifu Zhang, Mingzhao Li, Zhenmin Mo
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Publication number: 20190114745Abstract: 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: ApplicationFiled: April 1, 2016Publication date: April 18, 2019Applicant: Institute of Remote Sensing and Digital Earth, Chinese Academy of SciencesInventors: Lifu Zhang, Xuejian Sun, Xia Zhang
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Patent number: 10211766Abstract: The present disclosure relates to a multi-turn angle controlling method based on an absolute position encoder, including: obtaining a target angle according to a starting position and a target position, and obtaining number of times N that the target angle passes a predetermined position, determining whether an absolute value of the target angle being greater than 360 degrees, conducting a first operation mode upon determining that the absolute value of the target angle being greater than 360 degrees, incrementing M by one when the operation angle passes the predetermined position until M equals to N, M is a positive integer and an initial value of M is zero, and conducting a second operation mode when M equals to N, N is a positive integer greater than 1.Type: GrantFiled: May 9, 2017Date of Patent: February 19, 2019Assignee: UBTECH ROBOTICS CORP.Inventors: Youjun Xiong, Xi Bai, Wenhua Fan, Lifu Zhang
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Patent number: 10209093Abstract: A device sod a method for measuring servo gear idle position are provided. The method includes: outputting a start-up fixed force of a first rotation direction to an output shall of a servo under test, and recording a value of a start-up position of the output shaft when a position of a rotor of the servo under test changes for the first time; outputting a counterrotation force of a second rotation direction for rotating the output shaft to the output shaft, and recording a value of an counterrotation position of the output shaft when the rotor is in a stop status after a predetermined interval; and calculating a value of a servo gear idle position in a current measuring point, the value of the idle position is the absolute value of the difference between the value of the start-up position and the value of the counterrotation position.Type: GrantFiled: March 30, 2017Date of Patent: February 19, 2019Assignee: UBTECH ROBOTICS CORP.Inventors: Youjun Xiong, Lifu Zhang, Wenhua Fan, Zhongliang Wang
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Patent number: 10168210Abstract: Disclosed are a snapshot-type polarized hyperspectral camera and an imaging method. The camera comprises polarizers (11), an image sensor (12), and a spectra filter (13). The spectra filter (13) is located on the image sensor (12). The polarizers (11) are located on one side of the image sensor (12). The method comprises: shielding and transmitting incident light by means of polarizers (11), so as to obtain light signals (101) with different polarizing angles; receiving, by means of an image sensor (12), the light signals with different polarizing angles, which are obtained by the polarizers (11), and converting the light signals with different polarizing angles into electric signals (102); and receiving, by means of a spectra filter (13), the electric signals converted by the image sensor (12), and filtering the electric signals, so as to obtain high-frequency electric signals (103) with a preset wavelength.Type: GrantFiled: September 25, 2015Date of Patent: January 1, 2019Assignee: Institute of Remote Sensing and Digital Earth, Chinese Academy of SciencesInventors: Lifu Zhang, Hongming Zhang
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Patent number: 10031514Abstract: A method for servo locking control is provided. A servo enters a first lock state, and determines whether the current angular deflection values of the servo in a first preset period are all greater than a preset angular deflection value. When the current angular deflection values of the servo in the first preset period are all greater than the preset angular deflection value, the servo enters a second lock state, and determines whether the current angular changing values of the servo in a second preset period are all less than a preset angular changing value. When the current angular changing values of the servo in the second preset period are all less than the preset angular changing value, the servo enters the first lock state. A servo for performing the method for servo locking control is also provided.Type: GrantFiled: December 9, 2016Date of Patent: July 24, 2018Assignee: UBTECH ROBOTICS CORP.Inventors: Lifu Zhang, Tingshuang Huang, Youjun Xiong
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Patent number: 10031506Abstract: A motion control method includes: (a) obtaining a current position and a current velocity of a control object at a current time; (b) obtaining a current acceleration based on the current position and the current velocity, wherein the current acceleration has a positive correlation with a difference between the current position and a target position as well as a negative correlation with the current velocity; (c) controlling a motor for driving the control object utilizing the current acceleration; and (d) iteratively performing the steps (a)-(c) until the control object reaches the target position. A motion trajectory planning method and a motion control device are further provided. Through the above-mentioned way, the present disclosure could realize the smooth acceleration and smooth deceleration of the motor. As a result, smooth motion trajectory, less vibration, and stable motor with less overshoot could be achieved.Type: GrantFiled: January 18, 2017Date of Patent: July 24, 2018Assignee: UBTECH ROBOTICS CORP.Inventors: Wenhua Fan, Lifu Zhang, Xi Bai, Youjun Xiong
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Publication number: 20180188282Abstract: 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 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: ApplicationFiled: March 9, 2017Publication date: July 5, 2018Inventors: Youjun Xiong, Wenhua Fan, Lifu Zhang, Jianyun Xiao
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Publication number: 20180188707Abstract: 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: ApplicationFiled: July 3, 2017Publication date: July 5, 2018Inventors: Youjun Xiong, Lifu Zhang, Xi Bai, Wenhua Fan
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Publication number: 20180188074Abstract: The present disclosure relates to a multi-turns angle controlling method basing on magnetic coding, including: obtaining a target angle according to a starting position and a target position, and obtaining number of times N that the target angle passes a predetermined position, determining whether an absolute value the target angle being greater than 360 degrees, conducting a first operation mode upon determining that the absolute value of the target angle being greater than 360 degrees, incrementing M by one when the operation angle passes the predetermined position until M equals to N, M is a positive integer and an initial value of M is zero, and conducting a second operation diode when M equals to N, N is a positive integer greater than 1.Type: ApplicationFiled: May 9, 2017Publication date: July 5, 2018Inventors: Youjun Xiong, Xi Bai, Wenhua Fan, Lifu Zhang
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Publication number: 20180188073Abstract: A device sod a method for measuring servo gear idle position are provided. The method includes: outputting a start-up fixed force of a first rotation direction to an output shall of a servo under test, and recording a value of a start-up position of the output shaft when a position of a rotor of the servo under test changes for the first time; outputting a counterrotation force of a second rotation direction for rotating the output shaft to the output shaft, and recording a value of an counterrotation position of the output shaft when the rotor is in a stop status after a predetermined interval; and calculating a value of a servo gear idle position in a current measuring point, the value of the idle position is the absolute value of the difference between the value of the start-up position and the value of the counterrotation position.Type: ApplicationFiled: March 30, 2017Publication date: July 5, 2018Inventors: YOUJUN XIONG, Lifu Zhang, Wenhua Fan, Zhongliang Wang
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Publication number: 20180188136Abstract: 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: ApplicationFiled: July 4, 2017Publication date: July 5, 2018Inventors: HONGBO ZHU, Lifu Zhang, Youjun Xiong