Servo control method and apparatus and robot using the same

{
  "publication_number": "US10894319B2",
  "country": "US",
  "kind": "B2",
  "title": "Servo control method and apparatus and robot using the same",
  "abstract": "The present disclosure is provides a servo control method as well as an apparatus and a robot using the same. The method includes: obtaining a teeth force reduction multiple of a gear of a servo; creating a voltage queue based on the teeth force reduction multiple; calculating a target loading voltage corresponding to a current moment based on a voltage queue; and applying the target loading voltage on a motor of the servo, wherein the target loading voltage is for driving the motor of the servo to rotate. Through the above-mentioned method, the loading voltage can be effectively reduced when the servo is started, thereby protecting teeth of the gear of the servo and increasing the service life of the servo.",
  "claims": [
    "1. A computer-implemented control method for a servo of a robot, comprising executing on a processor of the robot steps of: obtaining a teeth force reduction multiple of a gear of the servo; creating a voltage queue based on the teeth force reduction multiple; calculating a target loading voltage corresponding to a current moment based on the voltage queue; and applying the target loading voltage on a motor of the servo, wherein the target loading voltage is for driving the motor of the servo to rotate.",
    "2. The method of claim 1, wherein the voltage queue comprises: {U1,U2,...,Ui,...,Un}; wherein, n is the teeth force reduction multiple, Ui is a preset loading voltage corresponding to the i-th moment, and i is a natural number greater than 1 and less than n.",
    "3. The method of claim 2, wherein the step of creating the voltage queue based on the teeth force reduction multiple comprises: setting an initial value of the preset loading voltage in the voltage queue corresponding to each moment to 0.",
    "4. The method of claim 2, wherein the step of calculating the target loading voltage corresponding to the current moment based on the voltage queue comprises: determining whether the current moment is a first moment after the servo is started; calculating the target loading voltage corresponding to the current moment through an equation of U1/n, in response to the current moment being the first moment after the servo is started; obtaining actual loading voltages corresponding to each moment between a moment the servo being started and the current moment to tale as historical loading voltages, in response to the current moment being not the first moment after the servo is started; and calculating the target loading voltage corresponding to the current moment based on the historical loading voltages through an equation of (U1+U2+... Uj+... +Um)/n; wherein, Uj equals to the actual loading voltage U(t j) corresponding to the j-th moment after the servo is started, Um equals to the actual loading voltage U(t m) corresponding to a previous moment of the current moment, and j is a natural number greater than 1 and less than m.",
    "5. A control apparatus for a servo of a robot, comprising; an obtaining unit configured to obtain a teeth force reduction multiple of a gear of the servo; a creation unit configured to create a voltage queue based on the teeth force reduction multiple; a calculation unit configured to calculate a target loading voltage corresponding to a current moment based on the voltage queue; and a control unit configured to apply the target loading voltage on a motor of the servo, wherein the target loading voltage is for driving the motor of the servo to rotate.",
    "6. The apparatus of claim 5, wherein the voltage queue comprises: {U1,U2,...,Ui,...,Un}; where, n is the teeth force reduction multiple, Ui is a preset loading voltage corresponding to the i-th moment, and i is a natural number greater than 1 and less than n.",
    "7. The apparatus of claim 6, wherein the creation unit comprises: a setting module configured to set an initial value of the preset loading voltage in the voltage queue corresponding to each moment to 0.",
    "8. The apparatus of claim 6, wherein the calculation unit comprises: a determining module configured to determine whether the current moment is a first moment after the servo is started; a first calculation module configured to calculate the target loading voltage corresponding to the current moment through an equation of U1/n, in response to the current moment being the first moment after the servo is started; an obtaining module configured to obtain actual loading voltages corresponding to each moment between a moment the servo being started and the current moment to take as historical loading voltages, in response to the current moment being not the first moment after the servo is started; and a second calculation module configured to calculate the target loading voltage corresponding to the current moment based on the historical loading voltages through an equation of (U1+U2+... Uj+... +Um)/n; wherein, Uj equals to the actual loading voltage U(t j) corresponding to the j-th moment after the servo is started, Um equals to the actual loading voltage U(t m) corresponding to a previous moment of the current moment, and j is a natural number greater than 1 and less than m.",
    "9. A robot, comprising; at least a servo; a memory; a processor; and one or more computer programs stored in the memory and executable on the processor, wherein the one or more computer programs comprise: instructions for obtaining a teeth force reduction multiple of a gear of the servo; instructions for creating a voltage queue based on the teeth force reduction multiple; instructions for calculating a target loading voltage corresponding to a current moment based on the voltage queue; and instructions for applying the target loading voltage on a motor of the servo, wherein the target loading voltage is for driving the motor of the servo to rotate.",
    "10. The robot of claim 9, wherein the voltage queue comprises: {U1,U2,...,Ui,...,Un}; where, n is the teeth force reduction multiple, Ui is a preset loading voltage corresponding to the i-th moment, and i is a natural number greater than 1 and less than n.",
    "11. The robot of claim 10, wherein the instructions for creating the voltage queue based on the teeth force reduction multiple comprise: instructions for setting an initial value of the preset loading voltage in the voltage queue corresponding to each moment to 0.",
    "12. The robot of claim 10, wherein the instructions for calculating the target loading voltage corresponding to the current moment based on the voltage queue comprise: instructions for determining whether the current moment is a first moment after the servo is started; instructions for calculating the target loading voltage corresponding to the current moment through an equation of U1/n, in response to the current moment being the first moment after the servo is started; instructions for obtaining actual loading voltages corresponding to each moment between a moment the servo being started and the current moment to take as historical loading voltages, in response to the current moment being not the first moment after the servo is started; and instructions for calculating the target loading voltage corresponding to the current moment based on the historical loading voltages through an equation of (U1+U2+... Uj+... +Um)/n; wherein, Uj equals to the actual loading voltage U(t j) corresponding to the j-th moment after the servo is started, Um equals to the actual loading voltage U(t m) corresponding to a previous moment of the current moment, and j is a natural number greater than 1 and less than m."
  ],
  "description_excerpt": "The present disclosure relates to control technology, and particularly to a servo control method as well as an apparatus and a robot using the same.\n\nIn general, the control of a servo adopts the classical PID (proportional integral derivative) algorithm, which obtains the loading voltage at two ends of the motor of the servo by calculating using the angle error and the gain. In the case that the servo is started, the angular error may be large, and the product of the gain and the angular error will be also large, so that a loading voltage applied on the two ends of the motor be large. Since at this time the loading voltage is very large while the starting time of the servo is very short, there will be a large acceleration, and then a large impact force will be generated to instantaneously hit the teeth of a gear of the servo and affect its years of use.\n\nTo describe the technical schemes in the embodiments of the present disclosure or in the prior art more clearly, the following briefly introduces the drawings required for describing the embodiments or the prior art. It should be understood that, the drawings in the following description merely show some embodiments of the present disclosure. For those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.\n\nFIG. 1 is a flow chart of an embodiment of a servo control method according to the present disclosure.\n\nFIG. 2 is a schematic block diagram of an embodiment of a servo control apparatus according to the present disclosure.",
  "cpc": [
    "B25J 9/161",
    "B25J 9/102",
    "B25J 9/1628",
    "B25J 9/1633",
    "G05B 19/414",
    "G05B 2219/41001",
    "G05F 1/10",
    "H02P 1/16"
  ],
  "ipc": [
    "B25J 19/00",
    "B25J 9/10",
    "B25J 9/16",
    "G05B 19/414",
    "G05F 1/10"
  ],
  "assignees": [
    "Ubtech Robotics Corp"
  ],
  "inventors": [
    "Yongping ZENG",
    "Youjun Xiong",
    "Zhongliang Wang",
    "Dong Liu",
    "Jianxin Pang"
  ],
  "filing_date": "2019-10-31",
  "publication_date": "2021-01-19",
  "grant_date": "2021-01-19",
  "priority_date": "2018-12-29",
  "application_number": "US-201916671164-A",
  "family_id": "71123812",
  "cited_by_count": 0,
  "citations": [
    "US6484068B1"
  ]
}