Active suspension with on-demand energy flow

• US 9,550,404 B2
• Filed: 03/14/2014
• Issued: 01/24/2017
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: ClearMotion, Inc.
• Original Assignee: Levant Power Corporation
• Inventors: Giovanardi, Marco, Tucker, Clive, Wendell, Ross J., Anderson, Zackary Martin, O'Shea, Colin Patrick, Gorelik, Vladimir, Sawyer, Tyson David, Leehey, Jonathan R., Schneider, Johannes, Driscoll, Robert, Neil, Patrick W., Avadhany, Shakeel
• Primary Examiner(s): Beck, Karen
• Application Number:
  US14/212,521
• Publication Number:
  US 20140265170A1
• Time in Patent Office: 1,047 Days
• Field of Search: 280/5.507, 280/5.515, 280/5.514, 701/37, 417/357, 417/231, 180/165, 318/376, 322/3, 388/816
• US Class Current: 1/1
• CPC Class Codes: B60G 15/10 and mechanical damper or dynamic damper
• CPC Class Codes: B60G 17/016 characterised by their responsiveness, when the vehicle is travelling, to specific motion, a specific condition, or driver input B60G17/017 takes precedence
• CPC Class Codes: B60G 2202/413 Hydraulic actuator
• CPC Class Codes: B60G 2204/11 Mounting of sensors thereon
• CPC Class Codes: B60G 2400/0511 Roll angle
• CPC Class Codes: B60G 2400/0521 Roll rate
• CPC Class Codes: B60G 2400/60 Load
• CPC Class Codes: B60G 2800/70 Estimating or calculating vehicle parameters or state variables
• CPC Class Codes: F04B 49/20 by changing the driving speed
• CPC Class Codes: F15B 13/0444 with rotary electric motor
• CPC Class Codes: F16K 11/065 with linearly sliding closure members
• CPC Class Codes: F16K 31/12 actuated by fluid fluid-actuated lift valves F16K1/126 ; fluid-actuated check valves F16K15/00; fluid-actuated safety valves F16K17/00
• CPC Class Codes: H02P 23/06 Controlling the motor in four quadrants

Abstract

Various embodiments related to hydraulic actuators and active suspension systems as well as their methods of use are described.

Claims

1. An active suspension system comprising:

a hydraulic actuator including a piston moveably positioned in a fluid filled housing between an extension volume and a compression volume;

a piston rod attached to the piston;

a hydraulic motor-pump in fluid communication with at least one of the extension volume and the compression volume; and

an electric motor operatively coupled to the hydraulic motor-pump, wherein in response to a sensed wheel event and/or a sensed body event the electric motor consumes power in a first mode of operation to operate the hydraulic motor-pump to control at least one pressure in the actuator to produce a pressure differential across the piston to apply force to the piston in an extension direction during at least a portion of an extension stroke or in a compression direction during at least a portion of a compression stroke.

2. The active suspension system of claim 1, wherein the active suspension system has a reflected system inertia and a system compliance, and wherein a product of the system compliance times the reflected system inertia is less than or equal to 0.0063 s⁻

2.

3. The active suspension system of claim 2, wherein a product of the system compliance times the reflected system inertia is greater than or equal to 2.5×

10<sup>−

6</sup> s<sup>−

2</sup>.

4. The active suspension system of claim 1, wherein a response time of the active suspension system is between 10 ms and 150 ms.

5. The active suspension system of claim 1, wherein a natural frequency of the active suspension system is between or equal to 2 Hz and 100 Hz.

6. The active suspension system of claim 1, further comprising a load holding device to hydraulically lock the actuator in place until the actuator is commanded to move.

7. The active suspension system of claim 1, wherein at least one of the hydraulic motor-pump, the electric motor, and a controller electrically coupled to the electric motor are remotely located relative to the hydraulic actuator.

8. The active suspension system of claim 1, wherein a pressure of the hydraulic actuator is substantially controlled by the hydraulic motor-pump operatively coupled to the electric motor.

9. The active suspension system of claim 1, wherein the electric motor is controlled using at least one of motor position, voltage, torque, impedance, frequency, and speed.

10. The active suspension system of claim 1, further comprising an accumulator that accepts a quantity of hydraulic fluid displaced by the piston rod volume during operation of the actuator.

11. The active suspension system of claim 1, wherein in response to the sensed wheel event and/or the sensed body event the electric motor consumes power in the first mode of operation to operate the hydraulic motor-pump to control pressure in the compression volume to apply force to the piston in an extension direction during at least a portion of an extension stroke.

12. The active suspension system of claim 1, wherein in response to the sensed wheel event and/or the sensed body event the electric motor consumes power in the first mode of operation to operate the hydraulic motor-pump to control at least one pressure in the actuator to apply force to the piston in an extension direction during at least a portion of an extension stroke and in a compression direction during at least a portion of a compression stroke.

13. The active suspension system of claim 1, wherein the hydraulic motor-pump operates in lockstep with the hydraulic actuator.

14. The active suspension system of claim 1, wherein an update frequency of a motor input used to control the electric motor is greater than or equal to a body event frequency.

15. The active suspension system of claim 14, wherein the update frequency of the motor input is greater than or equal to 0.5 Hz.

16. The active suspension system of claim 15, wherein the update frequency of the motor input is less than or equal to 1 kHz.

17. The active suspension system of claim 14, wherein the wheel event and/or body event frequency is between or equal to 0.5 Hz and 20 Hz.

18. The active suspension system of claim 1, wherein the electric motor is operated as a generator in a second mode of operation.

19. The active suspension system of claim 1, wherein the hydraulic actuator, hydraulic motor-pump, and electric motor are integrated with a single housing.

20. The active suspension system of claim 1, further comprising one or more valves located to control fluid flow between the hydraulic actuator and the hydraulic motor-pump.

78. The active suspension system of claim 12, wherein the active suspension system is in a semi-active mode when the actuator operates such that electrical energy is not supplied to the electric motor.

79. The active suspension system of claim 13, wherein in at least one operating mode of the active suspension system, force on the actuator is created by a pressure in the actuator that is at least partially decoupled from the pressure created by the motor-pump.

89. The active suspension system of claim 1 further comprising a valve that activates at a preset fluid flow rate of fluid flowing to the hydraulic motor-pump to divert at least a portion of the hydraulic fluid to bypass the hydraulic motor-pump, wherein the electric motor operates as an electric generator to apply a resisting torque on the hydraulic motor-pump in a third mode of operation where a resisting force is applied to the piston.

90. The active suspension system of claim 89 wherein the valve that activates at a preset fluid flow rate is a diverter valve.

91. The active suspension system of claim 20, wherein at least one of the one or more valves is selected from the group consisting of a diverter valve and a blow-off valve.

109. The method of claim 1 wherein the hydraulic motor-pump is a hydraulic pump.

21. A method for controlling an actuation system in an active suspension system, the method comprising:

in a first mode of operation controlling a motor input of an electric motor of the active suspension system in response to at least one of a road condition, a wheel event, and a body event;

driving a hydraulic motor-pump operatively coupled to the electric motor to produce pressurized fluid;

providing the pressurized fluid to at least one of an extension volume and a compression volume of an actuator to apply a pressure differential across a moving piston in the actuator, wherein the pressure differential applies a force to the piston in a direction of motion of the piston.

22. The method of claim 21, wherein the actuation system includes the electric motor, the hydraulic pump and the actuator, and wherein the actuation system has a reflected system inertia and a system compliance, and wherein a product of the system compliance times the reflected system inertia is less than or equal to 0.0063 s⁻

2.

23. The method of claim 22, wherein a product of the system compliance times the reflected system inertia is greater than or equal to 2.5×

10<sup>−

6</sup> s<sup>−

2</sup>.

24. The method of claim 21, wherein the actuation system includes the electric motor, the hydraulic pump and the actuator, and wherein a response time of the actuation system is between or equal to 10 ms and 150 ms.

25. The method of claim 21, wherein the actuation system includes the electric motor, the hydraulic pump and the actuator, and wherein a natural frequency of the actuation system is between or equal to 2 Hz and 100 Hz.

26. The method of claim 21, further comprising in a second mode of operation, controlling the electric motor of the actuator wherein the hydraulic motor-pump is not driven by the electric motor.

27. The method of claim 21, wherein the motor input is at least one of motor position, voltage, torque, impedance, frequency, and speed.

28. The method of claim 21, further comprising operating with the hydraulic actuator in all four quadrants of the force velocity domain of the hydraulic actuator.

29. The method of claim 21, wherein the actuator operates in at least three of four quadrants of the force velocity domain including compression damping, extension damping, active extension, and active compression.

30. The method of claim 29, wherein a command authority of the actuator in at least one passive quadrant includes operating the actuator such that electrical energy is not supplied to the electric motor.

31. The method of claim 21, further comprising operating the hydraulic motor-pump in lockstep with the hydraulic actuator during at least a first one operating mode of the active suspension system.

32. The method of claim 21, further comprising engaging a load holding device.

33. The method of claim 21, wherein the hydraulic motor controls extension and compression of the hydraulic actuator.

34. The method of claim 21, further comprising updating the motor input of the electrical motor at a frequency that is greater than or equal to a wheel event frequency or a body event frequency.

35. The method of claim 34, wherein the update frequency of the motor input is greater than or equal to 0.5 Hz.

36. The method of claim 35, wherein the update frequency of the motor input is less than or equal to 1 kHz.

37. The method of claim 34, wherein the wheel event and/or body event frequency is between or equal to 0.5 Hz and 20 Hz.

38. The method of claim 21, further comprising regenerating energy using the electric motor as a generator.

39. The method of claim 21, further comprising operating one or more valves located between the hydraulic actuator and the hydraulic motor-pump.

80. The active suspension system of claim 30, wherein the active suspension system is in a semi-active mode when the actuator operates such that electrical energy is not consumed by the electric motor.

92. The method of claim 39 wherein at least one of the one or more valves is selected from the group consisting of a diverter valve and a blow-off valve.

110. The method of claim 21 wherein the hydraulic motor-pump is a hydraulic pump.

115. The method of claim 21, wherein controlling the motor input further comprises controlling the motor input of the electric motor in response to a predicted road condition.

116. The method of claim 21, wherein controlling the motor input further comprises controlling the motor input of the electric motor in response to a predicted wheel event.

40. An active suspension system comprising:

a hydraulic actuator including a piston separating an extension volume and a compression volume;

a hydraulic motor-pump

an electric motor operatively coupled to the hydraulic motor;

a first flow path extending between the extension volume and the compression volume through the hydraulic motor-pump;

a second flow path between the extension volume and the compression volume;

a valve that during at least one mode of operation controls flow through the second flow path; and

a sensor for sensing an individual body event and/or an individual wheel event, wherein in response to the sensed individual body event and/or individual wheel event, the electric motor operates the hydraulic motor-pump to generate a differential pressure across the piston in an extension direction during at least a portion of an extension stroke and/or in a compression direction during at least a portion of a compression stroke.

41. The active suspension system of claim 40, wherein the sensed individual body event and/or individual wheel event is a sensed wheel event.

42. The active suspension system of claim 40, wherein the sensed individual body event and/or individual wheel event is a sensed body event.

43. The active suspension system of claim 40, wherein the active suspension system has a reflected system inertia and a system compliance, and wherein a product of the system compliance times the reflected system inertia is less than or equal to 0.0063 s⁻

2.

44. The active suspension system of claim 43, wherein a product of the system compliance times the reflected system inertia is greater than or equal to 2.5×

10<sup>−

6</sup> s<sup>−

2</sup>.

45. The active suspension system of claim 40, wherein a response time of the active suspension system is between or equal to 10 ms and 150 ms.

46. The active suspension system of claim 40, wherein a natural frequency of the active suspension system is between or equal to 2 Hz and 100 Hz.

47. The active suspension system of claim 40, wherein the hydraulic actuator, hydraulic motor-pump, and electric motor, are integrated with a single housing.

48. The active suspension system of claim 40, wherein at least one of the hydraulic motor-pump, the electric motor, and a controller electrically coupled to the electric motor are remotely located relative to the hydraulic actuator.

49. The active suspension system of claim 40, wherein the motor input is at least one of motor position, voltage, torque, impedance, frequency, and speed.

50. The active suspension system of claim 40, wherein the hydraulic actuator is controlled to operate in at least three of four quadrants of a force velocity domain of the hydraulic actuator.

51. The active suspension system of claim 50, wherein the hydraulic actuator is controlled to operate in all four quadrants of the force velocity domain of the hydraulic actuator.

52. The active suspension system of claim 50, wherein the four quadrants of the force velocity domain include compression damping, extension damping, active extension, and active compression.

53. The active suspension system of claim 40, wherein the hydraulic motor-pump operates in lockstep with the hydraulic actuator during at least a first operating mode of the active suspension system.

54. The active suspension system of claim 40, wherein an update frequency of the motor input is greater than or equal to a wheel event or a body event frequency.

55. The active suspension system of claim 54, wherein the update frequency of the motor input is greater than or equal to 0.5 Hz.

56. The active suspension system of claim 55, wherein the update frequency of the motor input is less than or equal to 1 kHz.

57. The active suspension system of claim 56, wherein the wheel event and/or body event frequency is between or equal to 0.5 Hz and 20 Hz.

58. The active suspension system of claim 40, wherein the electric motor is operated as a generator.

59. The active suspension system of claim 40, further comprising one or more valves located between the hydraulic actuator and the hydraulic motor-pump.

81. The active suspension system of claim 40, further comprising controlling a pressure in the hydraulic actuator when operating in at least two of four quadrants of a force velocity domain of the hydraulic actuator, wherein at least one of the two quadrants is selected from the group consisting of active compression and active extension.

82. The active suspension system of claim 40, further comprising controlling a pressure in the hydraulic actuator when operating in at least three of four quadrants of a force velocity domain of the hydraulic actuator.

83. The active suspension system of claim 40, wherein a command authority of the actuator in at least one passive quadrant includes operating the actuator such that electrical energy is not consumed by the electric motor;

wherein the active suspension system is in a semi-active mode when the actuator operates such that electrical energy is not supplied to the electric motor.

93. The active suspension system of claim 59 wherein at least one of the one or more valves is a diverter valve.

111. The method of claim 40 wherein the hydraulic motor-pump is a hydraulic pump.

60. A method for controlling an actuator in an active suspension system, the method comprising:

sensing an individual body and/or individual wheel event;

determining a desired electric motor input for an electric motor in response to the individual body and/or individual wheel event, wherein the electric motor is operatively coupled to a hydraulic motor-pump in fluid communication with an extension volume and a compression volume of the actuator, wherein a piston of the actuator is disposed between the extension volumes and compression volumes, and wherein the actuator has a response time of less than 150 ms;

supplying power to the electric motor in a first mode of operation to operate the hydraulic motor-pump to generate a differential pressure across the piston to apply force to the piston in an extension direction during at least a portion of an extension stroke and/or in a compression direction during at least a portion of a compression stroke.

61. The method of claim 60, wherein the active suspension system has a reflected system inertia and a system compliance, and wherein a product of the system compliance times the reflected system inertia is less than or equal to 0.0063 s⁻

2.

62. The method of claim 61, wherein a product of the system compliance times the reflected system inertia is greater than or equal to 2.5×

10<sup>−

6</sup> s<sup>−

2</sup>.

63. The method of claim 60, wherein a natural frequency of the active suspension system is between or equal to 2 Hz and 100 Hz.

64. The method of claim 60, wherein the motor input is at least one of motor position, voltage, torque, impedance, frequency, and speed.

65. The method of claim 60, further comprising operating with the hydraulic actuator in at least three quadrants of the force velocity domain of the hydraulic actuator.

66. The method of claim 60, further comprising operating with the hydraulic actuator in all four quadrants of the force velocity domain of the hydraulic actuator.

67. The method of claim 60, wherein the four quadrants of the force velocity domain include compression damping, extension damping, active extension, and active compression.

68. The method of claim 60, wherein a command authority of the actuator in at least one passive quadrant includes operating the actuator such that electrical energy is not consumed by the electric motor.

69. The method of claim 60, further comprising operating the hydraulic motor-pump in lockstep with the hydraulic actuator during at least one operating mode of the active suspension system.

70. The method of claim 60, wherein sensing an individual wheel event and/or an individual body event comprises sensing a wheel event.

71. The method of claim 60, wherein sensing an individual wheel event and/or an individual body event comprises sensing a body event.

72. The method of claim 60, further comprising updating the motor input at a frequency that is greater than or equal to a wheel event or a body event frequency.

73. The method of claim 72, wherein the update frequency of the motor input is greater than or equal to 0.5 Hz.

74. The method of claim 73, wherein the update frequency of the motor input is less than or equal to 1 kHz.

75. The method of claim 60, wherein the wheel event and/or body event frequency is between or equal to 0.5 Hz and 20 Hz.

76. The method of claim 60, further comprising regenerating energy using the electric motor as a generator.

77. The method of claim 60, further comprising operating one or more valves located to control fluid flow between the hydraulic actuator and the hydraulic motor-pump.

84. The active suspension system method of claim 68, wherein the active suspension system is in a semi-active mode when the actuator operates such that electrical energy is not supplied to the electric motor.

94. The method of claim 77, wherein the one or more valves include at least one valve selected from the group consisting of a diverter valve and a blow-off valve.

112. The method of claim 60 wherein the hydraulic motor-pump is a hydraulic pump.

85. An active suspension system of a vehicle comprising:

a hydraulic actuator including an extension volume and a compression volume separated by a piston, wherein the hydraulic actuator is interposed between a sprung mass and an unsprung mass of the vehicle;

a sensor that senses at least one of a wheel event and a body event;

a hydraulic motor-pump in fluid communication with the extension volume and the compression volume of the hydraulic actuator to control extension and/or compression of the hydraulic actuator;

at least one valve that controls flow of a portion of hydraulic fluid exchanged between the compression volume and the extension volume in at least one mode of operation; and

an electric motor operatively coupled to the hydraulic motor-pump, wherein operation of the electric motor controls a pressure differential across the piston to apply a force to the piston in response to the sensed wheel event and/or the sensed body event, wherein, in a first mode of operation, the electric motor operates the hydraulic actuator in at least one of active extension and active compression by applying the force in the direction of motion of the piston.

86. The active suspension system of claim 85, wherein in a second mode of operation the electric motor operates the hydraulic actuator in at least one of compression damping and extension damping by applying the force in a direction opposed to the motion of the piston.

87. The active suspension system of claim 86, wherein during the second mode of operation the hydraulic motor-pump drives the electric motor.

88. The active suspension system of claim 86, wherein the hydraulic motor moves in lockstep with the actuator during the second mode of operation.

95. The active suspension system of claim 85, wherein the at least one valve is selected from the group consisting of a diverter valve and a blow-off valve.

113. The method of claim 85 wherein the hydraulic motor-pump is a hydraulic pump.

96. A method for controlling a hydraulic actuator in an active suspension, the method comprising:

sensing a change in pressure of a hydraulic fluid;

operating an electric motor, operatively coupled to a hydraulic motor-pump that is in fluid communication with a volume in the actuator housing, based on the sensed pressure change, to generate pressurized fluid; and

using the pressurized fluid to apply a differential pressure across a piston in the actuator to produce a force on the piston in the direction of motion of the piston.

97. The method of claim 96, further comprising sensing an event selected from the group consisting of an individual event of a wheel and an individual event of a vehicle body, wherein the actuator is interposed between the vehicle body and the wheel.

98. The method of claim 97, further comprising responding to the event by controlling the differential pressure across the piston.

99. The method of claim 96, wherein during at least one mode of operation the fluid communication between the hydraulic motor-pump and the volume in the actuator occurs through a valve.

100. The method of claim 99, wherein the valve is at least one of a diverter valve and a blow-off valve.

101. The method of claim 96, wherein the change in pressure of the hydraulic fluid is a pressure change in the volume in the actuator housing.

102. The method of claim 96, wherein applying the differential pressure across the piston includes controlling a first pressure applied to a first side of the piston and/or a second pressure applied to a second opposing side of the piston, wherein the differential pressure is a difference between the first and second pressures.

103. The method of claim 96, wherein a response time of the active suspension system is between or equal to 10 ms and 150 ms.

104. The method of claim 96, wherein the valve is at least one of a diverter valve and a blow-off valve.

105. The method of claim 96, wherein the volume the hydraulic motor is in fluid communication with includes an extension volume on one side of the piston and a compression volume on an opposing side of the piston, and wherein operating the electric motor transfers fluid between the extension and compression volumes through the hydraulic motor-pump to generate the pressurized fluid and apply the differential pressure across the piston.

106. The method of claim 96, wherein the differential pressure is the difference in pressure between hydraulic fluid on a first side of the piston and hydraulic fluid on a second side of the piston.

107. The method of claim 96 wherein the force in the direction of motion of the piston is an extension force.

108. The method of claim 96 wherein the force in the direction of motion of the piston is a compression force.

114. The method of claim 96 wherein the hydraulic motor-pump is a hydraulic pump.