Steer-by-wire force sensing redundancy device and road sensing torque measuring method thereof

Abstract

The invention discloses a steering-by-wire force sensing redundancy device and a road sensing torque measuring method thereof, and belongs to the technical field of vehicle engineering, and the steering-by-wire force sensing redundancy device comprises a steering wheel, a steering column, a road sensing motor, a mechanical road sensing mechanism and a connection isolation mechanism; the mechanical road sensing mechanism comprises a lead screw nut, a nut limiting cylinder and a return spring; the steering column is provided with a threaded section; the lead screw nut is in threaded connection with the threaded section; the nut limiting cylinder is fixed with the frame; the steering column penetrates through the nut limiting cylinder and is rotationally connected with the nut limiting cylinder; the lead screw nut is arranged in the nut limiting cylinder, and the outer wall of the lead screw nut and the inner wall of the nut limiting cylinder are provided with limiting structures which are embedded with each other; the return spring is arranged between the lead screw nut and the nut limiting cylinder, and two ends of the return spring are respectively fixed with the lead screw nut and the nut limiting cylinder; the connecting and isolating mechanism is arranged between the steering column and the road feeling motor and can connect and isolate the steering column and the road feeling motor. The method has the advantages of safety, controllability, stability, high applicability and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle engineering and relates to a steering force sense redundancy device, in particular to a wire-controlled steering force sense redundancy device and a road sense torque measurement method thereof. Background Art

[0002] Driven by intelligent driving technology, higher requirements are being placed on chassis response speed. Based on this, the rise of drive-by-wire chassis technology has driven the development of new configurations and architectures for new energy vehicle chassis. As a critical component of a drive-by-wire chassis, steer-by-wire must achieve steering response speeds exceeding those of traditional chassis while also ensuring the functional safety of the steer-by-wire system. Current steer-by-wire systems mechanically connect the steering wheel, speed reducer, and road-sensing motor, which simulates steering torque and provides feedback to the driver. Compared to traditional chassis systems that mechanically transmit road conditions to the steering wheel, steer-by-wire systems provide the driver with a virtual sense of the road. When the road-sensing motor overheats and demagnetizes the permanent magnets, the road-sensing torque decreases or disappears, causing the driver to lose their sense of the vehicle's steering angle and affecting their maneuvering judgment. Summary of the Invention

[0003] The present invention provides a wire-controlled steer-force-feel redundancy device and a road-feel torque measurement method thereof, so as to overcome the defects of the prior art.

[0004] To achieve the above object, the present invention adopts the following technical solutions: In the first aspect, the present invention provides a wire-controlled steering force redundancy device, including a steering wheel, a steering column and a road sense motor, the steering wheel is fixed to the top of the steering column, and the road sense motor can drive the steering column to drive the steering wheel to rotate to provide virtual road sense, that is, to provide virtual road sense feedback for the driver; it also includes a mechanical road sense mechanism and a connection isolation mechanism; the mechanical road sense mechanism includes a screw nut, a nut limiting cylinder and a return spring; the steering column has a threaded section; the screw nut is threadedly connected to the threaded section; the nut limiting cylinder is fixed to the vehicle frame; the steering column passes through the nut limiting cylinder and is rotatably connected to the nut limiting cylinder; the screw nut is It is placed in the nut limiting cylinder, and the outer wall of the screw nut and the inner wall of the nut limiting cylinder have mutually embedded limiting structures. When the steering column rotates, the screw nut moves axially in the nut limiting cylinder; the return spring is arranged between the screw nut and the nut limiting cylinder, and the two ends are respectively fixed to the screw nut and the nut limiting cylinder, and can be extended and retracted axially with the movement of the screw nut; the connection and isolation mechanism is arranged between the steering column and the road sense motor, and can connect and isolate the steering column and the road sense motor; when connected, the road sense motor drives the steering column to rotate to provide virtual road sense; when isolated, the restoring force of the return spring provides virtual road sense.

[0005] Furthermore, the connection and isolation mechanism includes a reducer and a limiting assembly; the reducer includes a ring gear, a sun gear, several planetary gears and a planetary carrier; the sun gear is arranged in the ring gear, and several planetary gears are mounted on the planetary carrier and are arranged between the sun gear and the ring gear; the sun gear is meshed with the planetary gears, and the planetary gears are meshed with the ring gear; the steering column is arranged above the reducer, and the lower end is fixed to the ring gear; the planetary carrier is located below the several planetary gears and is rotatably connected to the steering bracket fixed to the vehicle frame; the road sense motor is arranged below the steering bracket, and the output shaft passes through the steering bracket and the planetary carrier and is fixedly connected to the sun gear; the limiting assembly can limit the relative movement of the planetary carrier and the steering bracket; when limited, the road sense motor is connected to the steering column, and the steering column is driven to rotate through the reducer to provide virtual road sense; when not limited, the road sense motor is isolated from the steering column.

[0006] Furthermore, the limiting component includes an electromagnetic lock capable of popping out a lock core; the electromagnetic lock is arranged on the lower side of the steering bracket, with the lock core facing upward; the planetary carrier has a lock hole; when the electromagnetic lock is powered off, the lock core pops out and extends into the lock hole, limiting the relative movement of the planetary carrier and the steering bracket; when the electromagnetic lock is powered on, the lock core retracts, and the movement of the planetary carrier and the steering bracket is isolated.

[0007] Furthermore, the limiting assembly also includes an electromagnetic lock fixing frame, a return spring and an emergency rope; the electromagnetic lock fixing frame is fixed to the lower side of the steering bracket; the return spring is arranged in the electromagnetic lock fixing frame; the electromagnetic lock is arranged in the electromagnetic lock fixing frame, above the return spring; the end of the emergency rope extends into the electromagnetic lock fixing frame from below, passes through the return spring, and is connected to the bottom end of the electromagnetic lock; when the electromagnetic lock is powered off, the emergency rope is pulled, and the emergency rope drives the electromagnetic lock to move downward so that its lock core disengages from the lock hole; when the emergency rope is released, the compressed return spring recovers, pushing the electromagnetic lock to move upward until its lock core re-extends into the lock hole.

[0008] Furthermore, the limiting assembly also includes a support rod, two pull rods, two connecting rods, a pulley and a pull rod rope; the support rod is fixed to the end of the steering bracket, inclined outward and upward, and the support rod is provided with a slide groove arranged along and passing through its length direction; the two pull rods are arranged on both sides of the support rod, and one end is rotatably connected to the lower end of the support rod; the two connecting rods are also arranged on both sides of the support rod, one end is rotatably connected to the other end of the pull rod on the same side, and the other end is slidably connected to the slide groove of the support rod; an ear plate is provided between the two pull rods; the other end of the emergency rope is connected to the ear plate; the pulley is installed on the frame and is located on the outside of the pull rod; the pull rod rope is wrapped around the pulley, and one end is connected between the ends of the two connecting rods and the pull rod; the other end of the pull rod rope is pulled on the outside of the pulley, and the pull rod rotates accordingly, driving the emergency rope to pull the electromagnetic lock downward.

[0009] Furthermore, an emergency pull ring is provided at the other end of the pull rod rope.

[0010] Furthermore, a downwardly recessed limit slot is provided at the upper end of the slide slot in the support rod. When the pull rod rope is pulled, the sliding end of the pull rod can be inserted into the limit slot to maintain the electromagnetic lock core out of the lock hole.

[0011] Furthermore, a transmission frame is fixed to the lower end of the steering column; the transmission frame is fixed to the ring gear; the bottom of the transmission frame is a plate-shaped structure, which closes the reducer from above.

[0012] Furthermore, the steering column is provided with an encoder for detecting the rotation angle of the steering column.

[0013] Furthermore, the nut limiting cylinder is equipped with a frame fixing plate, which is fixed to the frame through the frame fixing plate; the outer wall of the screw nut has a plurality of limiting protrusions, and the inner wall of the nut limiting cylinder has a plurality of limiting grooves arranged along the axial direction, the limiting protrusions and the limiting grooves correspond to each other and match each other, and the limiting protrusions are slidably connected in the corresponding limiting grooves.

[0014] In a second aspect, the present invention provides a method for measuring the road feel torque of the above-mentioned wire-controlled steering force redundancy device: when the road sense motor is working normally, the steering column is connected to the road sense motor through the connection isolation mechanism, the road sense motor provides a virtual road feel, and the road sense torque is the difference between the torque output by the road sense motor through the reducer and the torque output by the mechanical road sense mechanism; when the road sense motor has an abnormality, the connection isolation mechanism isolates the steering column from the road sense motor, the mechanical road sense mechanism provides a virtual road feel, and the road sense torque is the torque output by the mechanical road sense mechanism.

[0015] Furthermore, when the road sense motor works normally, the road sense torque is:

[0016] Where, T is the road feel torque, T 2 is the torque output by the ring gear, that is, the torque output by the road sense motor through the reducer. T 1 is the torque generated by the axial force of the return spring, that is, the torque output by the mechanical road sensing mechanism;

[0017] Where, T E is the output torque of the road sensing motor, i is the reduction ratio, η 2 is the transmission efficiency of the sun gear input and ring gear output;

[0018] Where, Za is the number of teeth of the sun gear, Z b is the number of teeth on the ring gear;

[0019] Where, P h is the elevation of the steering column thread section, η 1 is the transmission efficiency of the steering column from thrust to torque, and F1 is the axial force generated by the return spring;

[0020] Where, K is the elastic coefficient of the return spring, Δ x is the deformation of the return spring;

[0021] Where, θ is the steering wheel angle; When the road sense motor is abnormal, the road sense torque is:

[0022] The beneficial effects of the present invention are as follows: the present invention provides a redundant steering-by-wire force-feel device and a method for measuring road feel torque. First, the present invention provides a mechanical road feel mechanism that enables the driver to obtain road feel when the road feel motor fails. Specifically, a screw nut, a nut stop cylinder, and a return spring are provided on the steering column, and the steering operation itself drives the return spring to expand and contract, thereby obtaining road feel. Second, the present invention also provides a connection and isolation mechanism that can connect and isolate the steering column and the road feel motor. When the road feel motor is operating normally, the steering column and the road feel motor are connected, enabling the road feel motor to provide virtual road feel. If the road feel motor experiences an abnormality such as power failure, seizure, or speed loss, the steering column and the road feel motor are isolated, preventing the road feel motor from affecting steering wheel rotation and preventing the driver from misjudging the situation. Specifically, the connection and isolation mechanism achieves connection and isolation by controlling the state of the planetary carrier in the reducer via an electromagnetic lock. Furthermore, the present invention also provides related structures such as an emergency rope. If both the road feel motor and the electromagnetic lock malfunction, the planetary carrier state can be manually switched to isolate the fault. In addition, the present invention also provides a method for measuring road feel torque under different conditions. By obtaining the road feel torque, the parameters of the various structural components of the reducer and the mechanical road feel mechanism can be adjusted to obtain an ideal road feel that meets expectations to meet various driving needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the wire-controlled steering force redundancy device; Figure 2This is a schematic diagram of the structure of the wire-controlled steering force redundancy device (including the interior of the nut limit cylinder and the reducer); Figure 3 It is a schematic diagram of the structure of the steering column; Figure 4 It is a structural diagram of the screw nut; Figure 5 It is a structural diagram of the nut limiting cylinder; Figure 6 This is a schematic diagram of the structure connecting the isolation mechanism (including the interior of the electromagnetic lock fixing frame); Figure 7 It is a structural diagram of the transmission frame; Figure 8 This is a schematic diagram of the partial structural breakdown of the limiting component and planetary carrier when the electromagnetic lock is powered off; Figure 9 This is a schematic diagram of the partial structural breakdown of the limiting assembly and planetary carrier when the electromagnetic lock is energized; Figure 10 This is a schematic diagram of the structure of the wire-controlled steer-force-feel redundancy device from another perspective; Figure 11 This is a schematic diagram of the structure of the wire-controlled steer-force-feel redundancy device from another perspective; Figure 12 This is a schematic diagram of the partial structural breakdown of the restraining assembly and the planet carrier when the pull rod rope is pulled; The symbols in the accompanying drawings are: 1, steering wheel; 2, steering column; 21, threaded section; 22, transmission frame; 3, road sensing motor; 4, mechanical road sensing mechanism; 41, screw nut; 411, limiting protrusion; 42, nut limiting cylinder; 421. Frame fixing plate; 422. Limiting groove; 43. Return spring; 5. Connecting and isolating mechanism; 51. Reducer; 511. Ring gear; 512. Sun gear; 513. Planetary gear; 514. Planetary carrier; 5141. Lock hole; 52. Limiting assembly; 521. Electromagnetic lock; 5211. Lock cylinder; 522. Electromagnetic lock fixing bracket; 523. Return spring; 524. Emergency rope; 525. Support rod; 5251. Slide groove; 5252. Limiting slot; 526. Pull rod; 5261. Ear plate; 527. Connecting rod; 528. Pulley; 529. Pull rod rope; 5291. Emergency pull ring; 6. Steering bracket; 7. Encoder. DETAILED DESCRIPTION

[0024] The specific embodiments of the present invention are described below with reference to the accompanying drawings.

[0025] like Figure 1 As shown, this embodiment provides a wire-controlled steering force redundancy device, including a steering wheel 1, a steering column 2 and a road sense motor 3. The steering wheel 1 is fixed to the top of the steering column 2, and the road sense motor 3 can drive the steering column 2 to rotate to provide virtual road feel.

[0026] like Figure 1 As shown, the device further includes a mechanical road sensing mechanism 4 and a connection isolation mechanism 5.

[0027] like Figure 2 As shown, the mechanical road sensing mechanism 4 includes a screw nut 41, a nut limiting cylinder 42 and a return spring 43. Figure 3 As shown, the steering column 2 has a threaded section 21. The screw nut 41 is threadedly connected to the threaded section 21 of the steering column 2. The nut limiting cylinder 42 is fixed to the vehicle frame. Specifically, the nut limiting cylinder 42 is equipped with a frame fixing plate 421, and is fixed to the vehicle frame through the frame fixing plate 421. The steering column 2 passes through the bottom plate of the nut limiting cylinder 42, and is rotatably connected to the bottom plate of the nut limiting cylinder 42, and can rotate relative to the nut limiting cylinder 42. The screw nut 41 is arranged in the nut limiting cylinder 42, and the outer wall of the screw nut 41 and the inner wall of the nut limiting cylinder 42 have mutually interlocking limiting structures. As shown Figure 4 and Figure 5 As shown, in this embodiment, the outer wall of the screw nut 41 has a plurality of limiting protrusions 411, and the inner wall of the nut limiting cylinder 42 has a plurality of axially arranged limiting grooves 422. The limiting protrusions 411 correspond to and match the limiting grooves 422 one by one, and the limiting protrusions 411 are slidably connected in the corresponding limiting grooves 422. When the steering column 2 rotates, the screw nut 41 moves axially within the nut limiting cylinder 42. A return spring 43 is disposed between the screw nut 41 and the nut limiting cylinder 42, with its ends respectively fixed to the screw nut 41 and the nut limiting cylinder 42, and can expand and contract axially with the movement of the screw nut 41.

[0028] Connecting and isolating mechanism 5 is located between steering column 2 and road feel motor 3, connecting and isolating them. When connected, road feel motor 3 drives steering column 2 to rotate, providing virtual road feel. When isolated, rotating steering column 2 via steering wheel 1 moves lead screw nut 41, causing return spring 43 to extend or contract. The restoring force of the extended or contracted return spring 43 provides virtual road feel. This means that mechanical road feel mechanism 4 provides virtual road feel.

[0029] That is, when the road sense motor 3 is working normally, the steering column 2 is connected to the road sense motor 3 through the connection isolation mechanism 5, and the road sense motor 3 drives the steering column 2 to rotate to provide virtual road sense; when the road sense motor 3 malfunctions, the connection isolation mechanism 5 isolates the steering column 2 from the road sense motor 3, and at this time, the virtual road sense is provided through the mechanical road sense mechanism 4.

[0030] Specifically, such as Figure 2 and Figure 6 As shown, the connection isolation mechanism 5 includes a speed reducer 51 and a limiting assembly 52 .

[0031] like Figure 2 and Figure 6As shown, the reducer 51 includes a ring gear 511, a sun gear 512, three planetary gears 513 and a planet carrier 514. The sun gear 512 is arranged in the ring gear 511, and the three planetary gears 513 are mounted on the planet carrier 514, and can rotate respectively relative to the planet carrier 514. At the same time, the three planetary gears 513 are all arranged between the sun gear 512 and the ring gear 511. The sun gear 512 is engaged with the planetary gears 513, and the planetary gears 513 are engaged with the ring gear 511. The steering column 2 is arranged above the reducer 51, and the lower end is fixed to the ring gear 511, and the ring gear 511 receives the angular input of the steering wheel 1. Specifically, the lower end of the steering column 2 is fixed with a transmission frame 22, and the transmission frame 22 is fixed on the ring gear 511, that is, the steering column 2 is fixed to the ring gear 511 through the transmission frame 22. As shown Figure 7 As shown, the bottom of the transmission frame 22 is a plate-like structure. The transmission frame 22 is fixed to the ring gear 511 and seals the reducer 51 from above, preventing foreign matter from entering the reducer 51 from above and causing it to become stuck. The planetary carrier 514 is located below the three planetary gears 513 and is rotatably connected to the steering bracket 6, which is fixed to the vehicle frame. The road sensor motor 3 is located below the steering bracket 6. The output shaft passes upward through the steering bracket 6 and the planetary carrier 514 and is fixedly connected to the sun gear 512 via a flat key, transmitting torque to the sun gear 512.

[0032] The limiting component 52 can limit the relative movement of the planetary carrier 514 and the steering bracket 6. When limited, the road sense motor 3 is connected to the steering column 2, and drives the steering column 2 to rotate through the reducer 51 to provide virtual road sense. Specifically, when the relative movement of the planetary carrier 514 and the steering bracket 6 is limited, the planetary gears 513 can only rotate on their own and cannot revolve around the sun gear 512. At this time, the road sense motor 3 drives the sun gear 512 to rotate, and each planetary gear 513 rotates accordingly, thereby driving the ring gear 511 to rotate, and the steering column 2 rotates accordingly; when not limited, the road sense motor 3 is isolated from the steering column 2. Specifically, the planetary carrier 514 and When the steering bracket 6 moves relative to the steering bracket 6, the planetary carrier 514 and the steering bracket 6 are isolated from each other. The planetary carrier 514 can rotate relative to the steering bracket 6. Therefore, the planetary gears 513 have two degrees of freedom, which can rotate on their own and revolve around the sun gear 512. At this time, the road sense motor 3 drives the sun gear 512 to rotate, and the three planetary gears 513 revolve around the sun gear 512 and rotate on their own at the same time, without affecting the rotational movement of the ring gear 511, that is, they cannot drive the ring gear 511 to rotate. The road sense motor 3 is isolated from the steering column 2.

[0033] Specifically, such as Figure 6 、 Figure 8 and Figure 9 As shown, the limiting assembly 52 includes an electromagnetic lock 521 capable of popping out a lock core 5211. The electromagnetic lock 521 is arranged on the lower side of the steering bracket 6, with the lock core 5211 facing upward. The planetary carrier 514 has a lock hole 5141. Figure 8As shown, when the electromagnetic lock 521 is powered off, the lock core 5211 pops out, passes through the steering bracket 6, and extends into the lock hole 5141, limiting the relative movement of the planetary carrier 514 and the steering bracket 6; Figure 9 As shown, when the electromagnetic lock 521 is energized, the lock core 5211 retracts, and the planet carrier 514 and the steering bracket 6 are isolated from each other in motion, that is, the planet carrier 514 can rotate relative to the steering bracket 6.

[0034] When the road sensing motor 3 is working normally, the electromagnetic lock 521 is in a power-off state. At this time, the lock core 5211 is inserted into the lock hole 5141, the reducer 51 is operating normally, and the road sensing motor 3 drives the steering column 2 to rotate through the reducer 51 to provide virtual road sense; when the road sensing motor 3 is abnormal, the electromagnetic lock 521 is controlled to be energized, so that the lock core 5211 is disengaged from the lock hole 5141, thereby giving the reducer 51 two degrees of freedom, isolating the steering column 2 from the road sensing motor 3.

[0035] like Figure 6 As shown, the restraining assembly 52 also includes an electromagnetic lock mounting bracket 522, a return spring 523, and an emergency rope 524. The electromagnetic lock mounting bracket 522 is fixed to the underside of the steering bracket 6. The return spring 523 is disposed within the electromagnetic lock mounting bracket 522. The electromagnetic lock 521 is disposed within the electromagnetic lock mounting bracket 522, above the return spring 523. The end of the emergency rope 524 extends from below into the electromagnetic lock mounting bracket 522, passes through the return spring 523, and connects to the bottom end of the electromagnetic lock 521.

[0036] When the electromagnetic lock 521 is powered off, the emergency cord 524 is pulled, which drives the electromagnetic lock 521 downward, disengaging the lock core 5211 from the locking hole 5141 and compressing the return spring 523. When the emergency cord 524 is released, the compressed return spring 523 recovers, pushing the electromagnetic lock 521 upward until the lock core 5211 re-enters the locking hole 5141. If the electromagnetic lock 521 malfunctions, the lock core 5211 can be disengaged from the locking hole 5141 by pulling the emergency cord 524.

[0037] like Figure 6 、 Figure 10 and Figure 11As shown, in a preferred embodiment, the restraint assembly 52 further includes a support rod 525, two pull rods 526, two connecting rods 527, a pulley 528, and a pull rod rope 529. The support rod 525 is fixed to the end of the steering bracket 6, tilted outward and upward. A sliding groove 5251 runs along and through the support rod 525. Two pull rods 526 are positioned on either side of the support rod 525, with one end pivotally connected to the lower end of the support rod 525. Two connecting rods 527 are also positioned on either side of the support rod 525, with one end pivotally connected to the other end of the pull rod 526 on the same side and the other end slidingly connected to the sliding groove 5251 of the support rod 525. A lug 5261 is positioned between the two pull rods 526. The other end of the emergency rope 524, extending from the electromagnetic lock mounting bracket 522, is connected to the lug 5261. A pulley 528 is mounted on the vehicle frame, located outboard of the pull rod 526. The pull rod rope 529 is wound around the pulley 528, and one end is connected between the ends of the two connecting rods 527 and the pull rod 526.

[0038] like Figure 12 As shown, by pulling the other end of the pull rod rope 529 outside the pulley 528, the pull rod 526 rotates, driving the emergency rope 524 to pull the electromagnetic lock 521 downward. This configuration improves the flexibility of the structural layout, allowing the pulling end (i.e., the end of the pull rod rope 529) to be placed on the left side of the steering wheel 1, increasing operating space and facilitating operation.

[0039] Further preferably, an emergency pull ring 5291 is provided at the other end of the pull rod rope 529 to facilitate the driver to pull the pull rod rope 529 .

[0040] Furthermore, preferably, a downwardly recessed retaining slot 5252 is provided at the upper end of the slide slot 5251 in the support rod 525. When the pull rod rope 529 is pulled, the sliding end of the pull rod 526 can be engaged with the retaining slot 5252, thereby maintaining the lock cylinder 5211 of the electromagnetic lock 521 out of the locking hole 5141 without the need for manual maintenance by the driver. To repair an abnormal electromagnetic lock 521, the end of the pull rod 526 can be removed from the retaining slot 5252.

[0041] like Figure 1 and Figure 2 As shown, the steering column 2 is provided with an encoder 7 for detecting the rotation angle of the steering column 2. The encoder 7 is located below the nut limiting cylinder 42, and the housing is fixed to the nut limiting cylinder 42.

[0042] The operating principle of the steer-by-wire force-feel redundancy device is as follows: When the road-sensing motor 3 is operating normally, the electromagnetic lock 521 is de-energized, and the driver has not pulled the emergency pull ring 5291. This restricts movement between the steering bracket 6 and the planetary carrier 514 of the reducer 51. The road-sensing motor 3 drives the sun gear 512 of the reducer 51, which transmits torque to the ring gear 511 via the planetary gears 513. The ring gear 511 rotates the steering column 2 via the transmission frame 22, and the steering column 2 drives the steering wheel 1, providing the driver with road-sensing torque feedback. If an abnormality is detected in the road-sensing motor 3, the electromagnetic lock 521 is energized, and the lock cylinder 5211 of the electromagnetic lock 521 retracts and disengages the lock hole 5141 of the planetary carrier 514. When electromagnetic lock 521 malfunctions, the driver pulls the emergency ring 5291, causing the pull rod rope 529 to rotate the pull rod 526, which in turn drives the emergency rope 524 to pull electromagnetic lock 521 downward, disengaging the lock core 5211 of electromagnetic lock 521 from the lock hole 5141 of the planetary carrier 514. At this point, the planetary carrier 514 and steering bracket 6 of the speed reducer 51 move independently of each other, giving the speed reducer 51 two degrees of freedom. The movements of the sun gear 512 and the ring gear 511 do not affect each other, effectively isolating the road sensor motor 3 from the steering column 2.

[0043] Method for measuring road feel torque of a steer-by-wire force redundancy device: When the road sense motor 3 works normally, the steering column 2 is connected to the road sense motor 3 through the connection isolation mechanism 5. The road sense motor 3 provides a virtual road sense. The road sense torque is the difference between the torque output by the road sense motor 3 through the reducer 51 and the torque output by the mechanical road sense mechanism 4:

[0044] Where, T is the road feel torque, T 2 is the torque output by the ring gear 511, that is, the torque output by the road sense motor 3 through the reducer 51, T 1 is the torque generated by the axial force of the return spring 43, that is, the torque output by the mechanical road sensing mechanism 4.

[0045]

[0046] Where, T E Output torque for road sensing motor 3, i is the reduction ratio, η 2 is the transmission efficiency of the sun gear 512 input to the ring gear 511 output.

[0047]

[0048] Where, Z a The number of teeth of the sun gear is 512. Zb The number of teeth on the ring gear is 511.

[0049]

[0050] Where, P h is the elevation of the threaded section 21 of the steering column 2, η 1 is the transmission efficiency of the steering column 2 generating torque from thrust, and F1 is the axial force generated by the return spring 43.

[0051]

[0052] Where, K is the elastic coefficient of the return spring 43, Δ x is the deformation amount of the return spring 43.

[0053]

[0054] Where, θ is the turning angle of the steering wheel 1.

[0055] When the road sense motor 3 is abnormal, the isolation mechanism 5 is connected to isolate the steering column 2 from the road sense motor 3, and the mechanical road sense mechanism 4 provides a virtual road sense. The road sense torque is the torque output by the mechanical road sense mechanism 4:

[0056] By obtaining the road feel torque, the parameters of the various structural components of the speed reducer 51 and the mechanical road feel mechanism 4 can be adjusted to obtain an expected ideal road feel to meet various driving needs.

[0057] In the present invention, unless otherwise specified, the scientific and technical terms used herein have the meanings commonly understood by those skilled in the art.

[0058] It should be noted that the terms such as "upper", "lower", "left", "right", "front", "back", etc. cited in the invention are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0059] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A wire-controlled steering force redundant device, comprising a steering wheel (1), a steering column (2) and a road sense motor (3), wherein the steering wheel (1) is fixed to the top of the steering column (2), and the road sense motor (3) can drive the steering column (2) to rotate and provide a virtual road sense, characterized in that: It also includes a mechanical road sensing mechanism (4) and a connection isolation mechanism (5); The mechanical road sensing mechanism (4) comprises a screw nut (41), a nut limiting cylinder (42) and a return spring (43); The steering column (2) has a threaded section (21); the screw nut (41) is threadedly connected to the threaded section (21); The nut limiting cylinder (42) is fixed to the vehicle frame; the steering column (2) passes through the nut limiting cylinder (42) and is rotatably connected to the nut limiting cylinder (42); the screw nut (41) is arranged in the nut limiting cylinder (42), and the outer wall of the screw nut (41) and the inner wall of the nut limiting cylinder (42) have mutually engaged limiting structures, so that when the steering column (2) rotates, the screw nut (41) moves axially in the nut limiting cylinder (42); The return spring (43) is arranged between the screw nut (41) and the nut limiting cylinder (42), with both ends respectively fixed to the screw nut (41) and the nut limiting cylinder (42), and can be extended and retracted along the axial direction as the screw nut (41) moves; The connection and isolation mechanism (5) is arranged between the steering column (2) and the road sensing motor (3), and is capable of connecting and isolating the steering column (2) and the road sensing motor (3); When connected, the road sense motor (3) drives the steering column (2) to rotate to provide a virtual road sense; when isolated, the restoring force of the return spring (43) provides the virtual road sense.

2. The steer-by-wire force-feel redundancy device according to claim 1, characterized in that: The connection isolation mechanism (5) includes a speed reducer (51) and a limiting component (52); The speed reducer (51) includes a ring gear (511), a sun gear (512), a plurality of planetary gears (513), and a planetary carrier (514); the sun gear (512) is arranged in the ring gear (511), and the plurality of planetary gears (513) are mounted on the planetary carrier (514) and arranged between the sun gear (512) and the ring gear (511); the sun gear (512) is meshed with the planetary gears (513), and the planetary gears (513) are meshed with the ring gear (511); The steering column (2) is arranged above the reducer (51), and the lower end is fixed to the ring gear (511); The planet carrier (514) is located below the plurality of planetary gears (513) and is rotatably connected to a steering bracket (6) fixed to the vehicle frame; The road sensing motor (3) is arranged below the steering bracket (6), and the output shaft passes through the steering bracket (6) and the planetary carrier (514) upwards and is fixedly connected to the sun gear (512); The limiting component (52) is capable of limiting the relative movement of the planetary carrier (514) and the steering bracket (6); when limiting, the road sense motor (3) is connected to the steering column (2), and drives the steering column (2) to rotate through the reducer (51) to provide virtual road sense; When not restricted, the road sensing motor (3) is isolated from the steering column (2).

3. The steer-by-wire force-feel redundancy device according to claim 2, characterized in that: The limiting assembly (52) includes an electromagnetic lock (521) capable of ejecting a lock core (5211); The electromagnetic lock (521) is arranged on the lower side of the steering bracket (6), with the lock core (5211) facing upwards; The planet carrier (514) has a locking hole (5141); When the electromagnetic lock (521) is powered off, the lock core (5211) pops out and extends into the lock hole (5141), restricting the relative movement of the planetary carrier (514) and the steering bracket (6); when the electromagnetic lock (521) is powered on, the lock core (5211) retracts, isolating the movement of the planetary carrier (514) and the steering bracket (6).

4. The steer-by-wire force redundancy device according to claim 3, characterized in that: The limiting assembly (52) further includes an electromagnetic lock fixing frame (522), a return spring (523) and an emergency rope (524); The electromagnetic lock fixing frame (522) is fixed to the lower side of the steering bracket (6); the return spring (523) is arranged in the electromagnetic lock fixing frame (522); the electromagnetic lock (521) is arranged in the electromagnetic lock fixing frame (522) and is located above the return spring (523); the end of the emergency rope (524) extends from the bottom into the electromagnetic lock fixing frame (522), passes through the return spring (523), and is connected to the bottom end of the electromagnetic lock (521); When the electromagnetic lock (521) is in a power-off state, the emergency rope (524) is pulled, and the emergency rope (524) drives the electromagnetic lock (521) to move downward, so that its lock core (5211) is disengaged from the lock hole (5141); when the emergency rope (524) is released, the compressed return spring (523) is restored, pushing the electromagnetic lock (521) to move upward until its lock core (5211) re-enters the lock hole (5141).

5. The steer-by-wire force-feel redundancy device according to claim 4, characterized in that: The limiting assembly (52) further includes a support rod (525), two pull rods (526), two connecting rods (527), a pulley (528) and a pull rod rope (529); The support rod (525) is fixed to the end of the steering bracket (6), tilted outward and upward, and the support rod (525) is provided with a sliding groove (5251) arranged along the length direction and passing through the support rod (525); the two pull rods (526) are arranged on both sides of the support rod (525), one end of which is rotatably connected to the lower end of the support rod (525); the two connecting rods (527) are also arranged on both sides of the support rod (525), one end of which is rotatably connected to the other end of the pull rod (526) on the same side, and the other end of which is slidably connected to the sliding groove (5251) of the support rod (525); A lug plate (5261) is provided between the two pull rods (526); the other end of the emergency rope (524) is connected to the lug plate (5261); A pulley (528) is mounted on the vehicle frame and is located outside the pull rod (526); a pull rod rope (529) is wound around the pulley (528), with one end connected between the ends of the two connecting rods (527) and the pull rod (526); The other end of the pull rod rope (529) is pulled outside the pulley (528), and the pull rod (526) rotates accordingly, driving the emergency rope (524) to pull the electromagnetic lock (521) downward.

6. The steer-by-wire force-feel redundancy device according to claim 2, characterized in that: A transmission frame (22) is fixed to the lower end of the steering column (2); the transmission frame (22) is fixed to the gear ring (511); The bottom of the transmission frame (22) is a plate-shaped structure, which closes the reducer (51) from above.

7. The steer-by-wire force-feel redundancy device according to claim 1, characterized in that: The steering column (2) is provided with an encoder (7) for detecting the rotation angle of the steering column (2).

8. The steer-by-wire force-feel redundancy device according to claim 1, characterized in that: The nut limiting cylinder (42) is equipped with a frame fixing plate (421) and is fixed to the frame via the frame fixing plate (421); The outer wall of the screw nut (41) has a plurality of limiting protrusions (411), and the inner wall of the nut limiting cylinder (42) has a plurality of limiting grooves (422) arranged along the axial direction. The limiting protrusions (411) correspond to and match the limiting grooves (422) one by one, and the limiting protrusions (411) are slidably connected in the corresponding limiting grooves (422).

9. The method for measuring road feel torque of a steer-by-wire force sense redundancy device according to any one of claims 2 to 8, characterized in that: When the road sense motor (3) operates normally, the steering column (2) is connected to the road sense motor (3) via the connection isolation mechanism (5), the road sense motor (3) provides a virtual road sense, and the road sense torque is the difference between the torque output by the road sense motor (3) through the reducer (51) and the torque output by the mechanical road sense mechanism (4); When the road sense motor (3) is abnormal, the connecting isolation mechanism (5) isolates the steering column (2) from the road sense motor (3), and the mechanical road sense mechanism (4) provides a virtual road sense, and the road sense torque is the torque output by the mechanical road sense mechanism (4).

10. The method for measuring road feel torque of a steer-by-wire force sense redundancy device according to claim 9, characterized in that: When the road sensing motor (3) operates normally, the road sensing torque is: ； Where, T is the road feel torque, T 2 is the torque output by the ring gear (511), T 1 is the torque generated by the axial force of the return spring (43); Where, T E is the output torque of the road sensing motor (3), i is the reduction ratio, η 2 is the transmission efficiency of the sun gear (512) input to the ring gear (511) output; Where, Z a is the number of teeth of the sun gear (512), Z b is the number of teeth of the ring gear (511); Where, P h is the elevation of the threaded section (21) of the steering column (2), η 1 is the transmission efficiency of the steering column (2) generating torque from thrust, and F1 is the axial force generated by the return spring (43); Where, K is the elastic coefficient of the return spring (43), Δ x is the deformation of the return spring (43); Where, θ is the turning angle of the steering wheel (1); When the road sense motor (3) is abnormal, the road sense torque is: 。

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