Manipulating a computing device

Abstract

A manipulation calculation device that calculates values of state variables of a manipulation device (10) includes a storage device and an execution device. The execution device is configured to execute a bend angle acquisition process and a tilt angle calculation process, and the bend angle acquisition process is a process of acquiring a first bend angle and a second bend angle. The tilt angle calculation process is a process of calculating a tilt angle. The first bend angle is an angle formed between an input shaft of the manipulation device (10) and an intermediate shaft (18) of the manipulation device (10). The second bend angle is an angle formed between an output shaft of the manipulation device (10) and the intermediate shaft (18), and the tilt angle is a variable indicating an angle formed between an axial direction of the input shaft and a reference direction.

Description

Background of the Invention Technical Field

[0002] This invention relates to a manipulating computing device. Background Technology

[0004] For example, Japanese Unexamined Patent Application Publication No. 2008-49992 (JP 2008-49992A) describes a device capable of changing the tilt angle that defines the axial direction of an input shaft connected to a steering wheel. Furthermore, JP 2008-49992A describes a control device configured to perform steering control for assisting the steering wheels based on detection values ​​from a tilt angle sensor. Summary of the Invention

[0005] However, without a tilt angle sensor, the control unit cannot perform the desired control.

[0006] The following describes the methods that can solve this problem and their effects.

[0007] One aspect of the present invention relates to a control calculation device for calculating the values ​​of state variables relating to a control device. The control device includes a steering wheel, an input shaft, an intermediate shaft, an output shaft, a first universal joint, a second universal joint, and a steering wheel. The input shaft is connected to the steering wheel, the first universal joint is a member connecting the input shaft and the intermediate shaft, the second universal joint is a member connecting the intermediate shaft and the output shaft, and the steering wheel is configured to receive control torque input to the steering wheel via the input shaft, the intermediate shaft, and the output shaft. The control calculation device includes a storage device and an execution device. The storage device stores mapping data, which defines a mapping that outputs a tilt angle using a first bending angle and a second bending angle as inputs. The first bending angle is an angle formed between the input shaft and the intermediate shaft. The second bending angle is an angle formed between the output shaft and the intermediate shaft. The execution device is configured to perform a bending angle acquisition process and a tilt angle calculation process. The bending angle acquisition process is the process of acquiring the first bending angle and the second bending angle. The tilt angle calculation process is the process of calculating the tilt angle by inputting the first bending angle and the second bending angle into the mapping. Tilt angle is a variable that indicates the angle formed between the axial direction of the input shaft and the reference direction.

[0008] As described above, when the input shaft, intermediate shaft, and output shaft are connected via a universal joint, the change in tilt angle becomes a factor in the universal joint's change in bending angle. This means that the tilt angle can be determined from the first bending angle and the second bending angle. Therefore, using this configuration, the tilt angle can be calculated from the first bending angle and the second bending angle using a mapping that contains information about the relationship between the first bending angle and the second bending angle.

[0009] 2. In the manipulation calculation device according to the above aspects, the mapping data may include data indicating parallel vector components parallel to the reference direction. This mapping may include a position coordinate output mapping, a vector output mapping, and a tilt angle output mapping. The position coordinate output mapping may be a mapping that outputs the position coordinates of the steering wheel side end and the position coordinates of the rotation center of the first universal joint based on a first bending angle and a second bending angle. The vector output mapping may be a mapping that outputs an input axis vector as a vector determined based on the position of the rotation center of the first universal joint and the steering wheel side end. The tilt angle output mapping may be a mapping that outputs a tilt angle using an input axis vector and parallel vector components as input. The steering wheel side end may be the end on the steering wheel side of the two ends of the input axis.

[0010] The direction in which the rotation center of the first universal joint is connected to the steering wheel side end is the direction that defines the tilt angle. Therefore, using the above configuration, the tilt angle can be calculated by calculating the position coordinates of the rotation center of the first universal joint and the position coordinates of the steering wheel side end.

[0011] 3. In the control calculation device according to the above aspects, the position coordinate output mapping may be a mapping that outputs position coordinates as the solution to a simultaneous equation. The simultaneous equation may include a first bending angle relationship and a second bending angle relationship. The first bending angle relationship may be an expression indicating the relationship between the first bending angle and the dot product between a vector determined by the rotation center of the first universal joint and the steering wheel side end, and a vector determined by the rotation center of the first universal joint and the rotation center of the second universal joint. The second bending angle relationship may be an expression indicating the relationship between the second bending angle and the dot product between a vector determined by the rotation center of the first universal joint and the rotation center of the second universal joint, and a predetermined vector.

[0012] The paired inner product relates the length of the vector to the first and second bend angles. The length of the vector is determined by the position coordinates of the steering wheel side end and the rotation center of the first universal joint, which are unknown variables. Therefore, the equation can relate the unknown variables to the first and second bend angles.

[0013] 4. In the manipulation computing device according to the above aspects, the axial direction of the input shaft can be changed by rotating the input shaft about a predetermined portion different from the first universal joint, which serves as the center of rotation. The intermediate shaft can expand and contract by changing the axial direction of the input shaft. The mapping data may include the position coordinates of the predetermined portion. The simultaneous equations may include an equation representing the distance between the predetermined portion and the center of rotation of the first universal joint.

[0014] In the above configuration, since the intermediate shaft is retractable, the distance between the rotation centers of the first universal joint and the second universal joint changes. Therefore, it is difficult to form a simultaneous equation using the distance between the rotation centers of the first and second universal joints. Conversely, using the above configuration, by using an equation representing the distance between a predetermined portion and the rotation center of the first universal joint, an equation for adjusting the position coordinates of the rotation center of the first universal joint can be obtained.

[0015] 5. In the control calculation device according to the above aspects, the execution device can be configured to further perform control angle variable acquisition processing and output shaft angle variable acquisition processing. The control angle variable acquisition processing may be a process of acquiring the value of a control angle variable, which is a variable indicating the rotation angle of the steering wheel. The output shaft angle variable acquisition processing may be a process of acquiring the value of an output shaft angle variable, which is a variable indicating the rotation angle of the output shaft. The bending angle acquisition processing may be a process of calculating a first bending angle and a second bending angle by using the values ​​of the control angle variable and the output shaft angle variable as inputs.

[0016] Since the relationship between the output shaft's rotation angle and the operating angle depends on the bend angle between the input shaft and the intermediate shaft, and the bend angle between the intermediate shaft and the output shaft, the paired bend angles can be determined from the output shaft's rotation angle and the operating angle. In the above configuration, taking this into account, the values ​​of the operating angle variable and the output shaft angle variable can be used as inputs to calculate the first bend angle and the second bend angle.

[0017] 6. In the manipulation calculation device according to the above aspects, the manipulation angle variable acquisition process may include the process of acquiring different values ​​of the manipulation angle variable. The output axis angle variable acquisition process may include the process of acquiring the value of the output axis angle variable, wherein the value of the output axis angle variable is synchronized with the different values ​​of the manipulation angle variable. Relationship constraint data may be stored in a storage device. The relationship constraint data may be data that defines a relational expression. The relational expression may be an expression defining the relationship between the values ​​of the manipulation angle variable and the values ​​of the output axis angle variable and the first bending angle and the second bending angle. The bending angle acquisition process may include the process of calculating the first bending angle and the second bending angle by inputting the different values ​​of the manipulation angle variable and the values ​​of the output axis angle variable into the relational expression using the least squares method, wherein the value of the output axis angle variable is synchronized with the different values ​​of the manipulation angle variable.

[0018] A physical relationship is established between the control angle and the rotation angle of the output shaft, and the first and second bend angles. Therefore, using the above configuration, the first and second bend angles can be calculated using the least squares method as unknown variables in the relationship.

[0019] 7. In the control calculation device according to the above aspects, the control device may include an actuator configured to generate power to steer the steering wheels. The control device may be configured to perform operation processing and response processing. Operation processing may be processing that operates the actuator in response to operation of the steering wheel. Response processing may be processing that reflects the tilt angle in the operation of the actuator.

[0020] The relationship between the steering angle and the rotation angle of the output shaft, as well as the relationship between the steering torque and the torque applied to the output shaft, can change depending on the tilt angle. Therefore, if the actuator operates in response to steering wheel input without considering the tilt angle, there is a problem that the actuator's operation may not be appropriate depending on the tilt angle. In view of this, by incorporating the tilt angle into the operation processing using the above configuration, the operation processing can be made more suitable. Attached Figure Description

[0021] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which the same reference numerals denote the same elements, and in the drawings:

[0022] Figure 1 This is a view showing the construction of a control system according to one embodiment;

[0023] Figure 2 This is a view showing the construction of the first universal joint according to an embodiment;

[0024] Figure 3 This is a block diagram illustrating the process performed by the control device according to an embodiment;

[0025] Figure 4 This is a flowchart illustrating the process executed by the control device according to an embodiment;

[0026] Figure 5 This is a flowchart illustrating the process executed by the control device according to an embodiment; and

[0027] Figure 6 It is a view that limits the coordinates used for the calculation process of the tilt angle according to the implementation method. Detailed Implementation

[0028] One embodiment of manipulating a computing device is described below with reference to the accompanying drawings.

[0029] System Configuration

[0030] like Figure 1As shown, the control device 10 is a device configured to steer the steering wheel 36 by cooperating with the steering torque input by the driver to the steering wheel 12 and the power of the steering actuator 40. The control device 10 is an electrically assisted control device. In the following description, the operation of the steering wheel 12 in the right or left direction is referred to as "control".

[0031] The steering wheel 12 is fixed to the column shaft 14. The column shaft 14 is mechanically connected to the intermediate shaft 18 via a first universal joint 16. The intermediate shaft 18 has a known retractable configuration. Of the two ends of the intermediate shaft 18 along its axial direction, the end opposite to the end connected to the first universal joint 16 is connected to the pinion shaft 22 via a second universal joint 20.

[0032] Figure 2 The construction of a first universal joint 16 is shown. The first universal joint 16 includes a first yoke 16a, a second yoke 16b, and a joint cross shaft 16c. The joint cross shaft 16c has a cross shape. The joint cross shaft 16c connects the first yoke 16a and the second yoke 16b to each other, allowing the first yoke 16a and the second yoke 16b to rotate. The first yoke 16a is fastened to the end of a column shaft 14 by bolts (not shown). Note that the first yoke 16a can be welded to the end of the column shaft 14. The second yoke 16b is fixed to the end of an intermediate shaft 18 by welding.

[0033] Note that the construction of the second universal joint 20 is similar to that of the first universal joint 16, and therefore, the construction of the second universal joint 20 is not described herein. Return to References Figure 1 The pinion shaft 22 is positioned at a predetermined crossing angle with the rack shaft 30. The rack and pinion mechanism 32 is configured such that rack teeth 30a formed on the rack shaft 30 mesh with pinion teeth 22a formed on the pinion shaft 22. Furthermore, corresponding tie rods 34 are connected to the opposite ends of the rack shaft 30. The respective distal ends of the tie rods 34 are connected to corresponding steering knuckles (not shown), to which steering wheels 36 are assembled. Through the rack and pinion mechanism 32, the rotational operation of the steering wheel 12 is converted into a displacement operation of the rack shaft 30 in the axial direction. When the axial displacement operation is transmitted to the steering knuckle via the tie rods 34, the steering angle of the steering wheels 36 changes. Note that the steering angle is the steering angle of the tires of the steering wheels 36.

[0034] The steering actuator 40 includes an auxiliary motor 42 as a drive source, a transmission mechanism 44 configured to transmit the torque of the auxiliary motor 42, and a ball screw mechanism 46. The ball screw mechanism 46 converts the torque of the auxiliary motor 42 transmitted via the transmission mechanism 44 into a force that displaces the rack shaft 30 in the axial direction. As an example, the auxiliary motor 42 is a three-phase brushless motor. The output voltage of the inverter 60 is applied to the terminals of the auxiliary motor 42.

[0035] Control device 50 operates inverter 60 to control the amount of control applied to steering wheel 36, which is the controlled object. Control device 50 controls the aforementioned amount of control by referencing the rotation angle θm of auxiliary motor 42 detected by rotation angle sensor 70. Furthermore, control device 50 references the currents iu, iv, and iw output from inverter 60. Note that the currents iu, iv, and iw can be determined by the amount of voltage drop across the respective shunt resistors in the branch circuit of inverter 60. Additionally, control device 50 references the torque Trq applied to steering wheel 12, detected by torque sensor 72.

[0036] The control unit 50 includes a PU 52 and a storage unit 54. The PU 52 is a software processing unit that includes at least one of a CPU, GPU, and TPU. The PU 52 is an example of an actuator. The higher-level ECU 80 is an electronic control unit configured to generate commands higher than those of the control unit 50 regarding vehicle control. The higher-level ECU 80 references the steering angle θh detected by the steering angle sensor 82. The steering angle θh is the rotation angle of the steering wheel 12. In other words, the steering angle θh is the rotation angle of the column shaft 14.

[0037] The control unit 50 and the host ECU 80 can communicate with each other. The control unit 50 can receive the control angle θh acquired by the host ECU 80. However, the sampling period of the control angle θh is longer than that of the rotation angle θm.

[0038] Auxiliary control

[0039] Figure 3 The process performed by the control device 50 is shown. Figure 3 The processing shown is achieved, for example, by PU 52 repeatedly executing the auxiliary control program 54a stored in storage device 54 at predetermined cycles.

[0040] The pinion angle calculation process M10 uses the rotation angle θm as input to calculate the pinion angle θp, where θp is the rotation angle of the pinion shaft 22. The control angle calculation process M12 uses the pinion angle θp as input to calculate the control angle θh. The control angle calculation process M12 uses data stored in... Figure 1 The process of calculating the operating angle θh is defined by the relational constraint data 54b in the storage device 54 shown. The relational constraint is expressed by equation (c1) as follows. The relational constraint takes the pinion angle θp as the independent variable and the operating angle θh as the dependent variable.

[0041]

[0042] Here, the bending angle α1 of the first universal joint 16, the bending angle α2 of the second universal joint 20, and the difference angle variable ψ are used. The bending angle α1 of the first universal joint 16 is the angle formed between the axial direction of the column shaft 14 and the axial direction of the intermediate shaft 18. Similarly, the bending angle α2 of the second universal joint 20 is the angle formed between the axial direction of the intermediate shaft 18 and the axial direction of the pinion shaft 22. The difference angle variable ψ is “90-ξ+ε”. Here, “ξ” is the angle formed between a plane parallel to both the axial directions of the column shaft 14 and the intermediate shaft 18, and a plane parallel to both the axial directions of the intermediate shaft 18 and the pinion shaft 22. Furthermore, “ε” is the phase difference between the yoke on the intermediate shaft 18 side of the two yokes of the first universal joint 16 and the yoke on the intermediate shaft 18 side of the two yokes of the second universal joint 20. The phase difference used herein indicates the deviation between the rotation angles around the axial direction of the intermediate shaft 18.

[0043] Equation (c1) is derived by applying the equation that defines the relationship between the bending angle and the rotation angle of the paired yokes in the universal joint to the first universal joint 16 and the second universal joint 20.

[0044] In other words, equation (c1) is derived by using a combination of equations (c2) and (c3).

[0045] tanθ2=cosα1·tanθh...(c2)

[0046] tan(θp′)=cosα2·tan(θ2+ψ)...(c3)

[0047] Note that "θ2" is the rotation angle of the intermediate shaft 18. Additionally, "θp" represents the phase difference between the pinion angle θp and "θh". More specifically, equation (c4) is derived from equations (c2) and (c3).

[0048] θp′=arctan(tan[arctan{tan(θh)·cos(α1)}+ψ]·cos(α2))...(c4)

[0049] Therefore, the pinion angle θp is expressed by equation (c5) as follows.

[0050] θp=θp′-arctan{tan(ψ)·cos(α2)}...(c5)

[0051] By removing θp′ from equations (c4) and (c5), equation (c1) can be obtained.

[0052] The compensation torque calculation process M20 calculates the steering torque Th by removing the gravitational influence from the torque Trq. That is, the rotation center of the steering wheel 12 is offset from the center of gravity of the steering wheel 12. Therefore, the torque Trq detected by the torque sensor 72 is the resultant force of the torque input to the steering wheel 12 by the driver and gravity. The compensation torque calculation process M20 calculates the steering torque Th by removing the gravitational component included in the torque Trq.

[0053] Here, the magnitude of gravity contributing to the torque Trq changes periodically depending on the control angle θh. Therefore, the compensation torque calculation process M20 is a process that uses the control angle θh as input to calculate the control torque Th.

[0054] At the same time, the column axis 14 can be rotated around Figure 1 The tilt rotation center OT shown in the diagram rotates. Therefore, the position of the steering wheel 12 is adjustable. Note that when the tilt angle θtl, which is the amount of rotation around the tilt rotation center OT, changes, even if the steering angle θh is the same, the magnitude of gravity contributing to the torque Trq will change. Therefore, the compensation torque calculation process M20 is a process that uses the tilt angle θtl as input to calculate the steering torque Th.

[0055] The auxiliary torque calculation process M22 calculates the auxiliary torque Ta using the steering torque Th as input. In other words, the auxiliary torque calculation process M22 processes the auxiliary torque Ta by adjusting its magnitude according to the steering torque Th, thus achieving an appropriate magnitude of auxiliary torque Ta for the driver's intended steering. The auxiliary torque calculation process M22 can also process the auxiliary torque Ta such that when the steering torque Th is large, its magnitude is equal to or greater than when the steering torque Th is small. Furthermore, the auxiliary torque calculation process M22 can also process the auxiliary torque Ta by setting different values ​​for steering and for turning, even when the steering torque Th is the same.

[0056] The operation signal output processing M24 processes data as follows: using the auxiliary torque Ta, rotation angle θm, and currents iu, iv, and iw as inputs, it generates and outputs the operation signal MS of the inverter 60 for controlling the torque of the auxiliary motor 42 to the auxiliary torque Ta. Note that in practice, the operation signal MS is the operation signal for each switching element of the inverter 60.

[0057] Estimation of tilt angle

[0058] As described above, the tilt angle θtl changes. When the tilt angle θtl changes, the first bending angle α1, the second bending angle α2, and the difference angle variable ψ also change. Therefore, in this embodiment, the first bending angle α1, the second bending angle α2, the difference angle variable ψ, and the tilt angle θtl are not values ​​explicitly determined by the specification, but rather variables that change when the driver changes the tilt angle θtl.

[0059] The details of the estimation process for these variables are described below. Figure 4 , Figure 5 The estimation process is illustrated. Figure 4 , Figure 5 The processing shown is achieved, for example, by PU 52 repeatedly executing the auxiliary control program 54a stored in storage device 54 at predetermined cycles.

[0060] exist Figure 4 In the series of processes shown, PU 52 first determines whether the update flag F is "1" (S10). If the update flag F is "1", the update flag indicates that the process of updating the variable should be performed. If the update flag F is "0", the update flag indicates that the process of updating the variable should not be performed.

[0061] If PU 52 determines that the update flag F is "0" (S10: No), PU 52 determines whether the activation switch has just switched from the off state to the on state (S12). The activation switch is a switch used to put the vehicle into an operable state. For example, if only an internal combustion engine is provided as the thrust generating device in the vehicle, the activation switch may be an ignition switch. Alternatively, if the thrust generating device in the vehicle includes an electric motor, the activation switch may be a switch configured to open and close the circuit between the electric motor and the battery.

[0062] If PU 52 determines that the activation switch has switched to the ON state (S12: Yes), PU 52 substitutes "1" into the update flag F (S14). If PU 52 makes a positive determination in the process of S10, or if PU 52 ends the process of S14, PU 52 acquires the pinion angle θp (S16). Additionally, PU 52 acquires the control angle θh through communication with the host ECU 80 (S18). Then, PU 52 stores a set of pinion angles θp and control angles θh in the storage device 54 (S20). The pinion angles θp and control angles θh are synchronized data. This can be achieved, for example, by... Figure 5 The series of processes shown are implemented by setting the period of the receiving interval of the manipulation angle θh.

[0063] Subsequently, PU 52 determines whether the difference between the maximum and minimum absolute values ​​of the manipulation angle θh stored in the processing of S20 is equal to or greater than a predetermined value Δth (S22). When PU 52 determines that the difference is the predetermined value Δth or greater (S22: yes), PU 52 obtains the first bending angle α1, the second bending angle α2, and the difference angle variable ψ by least squares method (S24).

[0064] In other words, for each set of pinion angle θp and operating angle θh stored in the processing of S20, PU 52 calculates the square of the difference between the value obtained by substituting the pinion angle θp into the right side of equation (c1) and the operating angle θh. Then, PU 52 searches for a first bend angle α1, a second bend angle α2, and a difference angle variable ψ that minimize the sum of the corresponding squares of the differences between each set of pinion angles θp and operating angles θh stored in the processing of S20.

[0065] Subsequently, PU 52 updates the first bend angle α1, the second bend angle α2, and the difference angle variable ψ (S26) defined in relational constraint data 54b. Then, PU 52 calculates... Figure 6 The corresponding coordinates of points A and B are shown in the figure. Figure 5 (S28 in the text).

[0066] exist Figure 6 In this diagram, the axial center of the end of the column shaft 14 connected to the end side of the steering wheel 12 is designated as point A. Additionally, point B is the center of the connector cross shaft 16c of the first universal joint 16. Point C is the center of the connector cross shaft of the second universal joint 20. Furthermore, point D is a point on the rotation center axis of the pinion shaft 22. Point D is introduced, together with point C, to define a vector parallel to the pinion shaft 22.

[0067] As described above, the distance between point B and point C changes as the intermediate axis 18 expands and contracts with the tilt angle θtl. Meanwhile, since point B rotates around the tilt rotation center OT, the distance between the tilt rotation center OT and point B does not change with the tilt angle θtl. Similarly, the distance between the tilt rotation center OT and point A also remains unchanged. Considering these factors, the coordinates of point A (xa, ya, za) and the coordinates of point B (xb, yb, zb) are six unknowns, which are calculated using six simultaneous equations Eq1 to Eq6.

[0068] Here, equation Eq1 is an equation concerning the square of the length between the tilt rotation center OT and point A. The square of the length is a predetermined fixed value. Additionally, the coordinates (xO, yO, zO) representing the tilt rotation center OT are also fixed values. Stored in... Figure 1 The mapping data 54c in the storage device 54 shown includes data about the coordinates of the tilt rotation center OT, and data about the square of the length.

[0069] Equation Eq2 is obtained by substituting the coordinate components of point A into the equation representing the plane containing points A and B. This plane does not change with the tilt angle θtl. Mapping data 54c includes data that defines the equation representing this plane.

[0070] Equation Eq3 is expressed by using the first bending angle α1 to represent the dot product of the vector moving from point B to point A and the vector moving from point B to point C. Mapping data 54c includes data defining the coordinates of point C.

[0071] Equation Eq4 is an equation concerning the square of the length between the tilt rotation center OT and point B. The square of the length is a predetermined fixed value. Mapping data 54c includes data related to the square of the length.

[0072] Equation Eq5 is obtained by substituting the coordinate components of point B into the equation representing the plane containing points A and B. Equation Eq6 is obtained by using the second bending angle α2 to represent the dot product of the vector moving from point C to point B and the vector moving from point C to point D.

[0073] Subsequently, PU 52 calculates the vector from point B to point A using the coordinate components obtained from the processing in S28 (S30). Then, PU 52 calculates the tilt angle θtl (S32). The tilt angle θtl is quantized as the direction of movement from point B to point A relative to... Figure 6 The angle formed by the direction of travel from reference point B0 to reference point A0 is shown as an example. Reference point B0 is the reference point for point B. Reference point A0 is the reference point for point A. When the steering wheel 12 is in the reference position, point A is placed at reference point A0. Conversely, when the steering wheel 12 is in the reference position, point B is placed at reference point B0.

[0074] PU 52 calculates the tilt angle θtl based on the dot product of the vector moving from reference point B0 to reference point A0 and the vector moving from point B to point A, the distance between reference point B0 and reference point A0, and the distance between point B and point A. Mapping data 54c includes data defining the vector moving from reference point B0 to reference point A0.

[0075] Then, PU 52 substitutes "0" into the update flag F (S34). Note that PU 52 ends a cycle when PU 52 finishes processing S34, or when PU 52 makes a negative confirmation in processing S12 or S22. Figure 4 , Figure 5 The series of processes shown in the figure.

[0076] Operation and effects of this implementation method

[0077] PU 52 estimates the first bend angle α1, the second bend angle α2, and the difference angle variable ψ based on relation (c1) using sequential data of the control angle θh and the pinion angle θp. Then, PU 52 calculates the coordinate components of points A and B using the first bend angle α1, the second bend angle α2, and the difference angle variable ψ. Next, PU 52 calculates the tilt angle θtl based on the coordinate components of points A and B. Using the tilt angle θtl, PU 52 can accurately remove the influence of gravity on the torque Trq and determine the control torque Th.

[0078] Correspondence

[0079] The correspondence between the content described in the above embodiments and the content described in the field of "Summary of the Invention" is as follows. In the following description, the correspondence will be described for each number of the method for solving the problem described in the field of the Summary of the Invention.

[0080] [1] The manipulation calculation device corresponds to the control device 50. The input shaft corresponds to the column shaft 14. The output shaft corresponds to the pinion shaft 22. The bending angle acquisition process corresponds to the processes S20 to S24. The tilt angle calculation process corresponds to the processes S28 to S32. The mapping data corresponds to the mapping data 54c. The mapping corresponds to the mapping achieved through the processes S28 to S32.

[0081] [2] The rotation center of the first universal joint corresponds to point B. The rotation center of the second universal joint corresponds to point C. The vector parallel to the reference direction corresponds to the vector moving from reference point B0 to reference point A0. The position coordinate output mapping corresponds to the mapping implemented through the process of S28. The vector output mapping corresponds to the mapping implemented through the process of S30. The tilt angle output mapping corresponds to the mapping implemented through the process of S32.

[0082] [3] The first bending angle relationship corresponds to equation Eq3. The second bending angle relationship corresponds to equation Eq6. The predetermined vector corresponds to the vector moving from point C to point D.

[0083] [4] "The equation representing the distance between the predetermined part and the rotation center of the first universal joint" corresponds to equation Eq4.

[0084] [5] The bending angle acquisition process corresponds to the process in S24. The manipulation angle variable acquisition process corresponds to the process in S18, which is repeated periodically until a definite determination is made in the process in S22. The output shaft angle variable acquisition process corresponds to the process in S16, which is repeated periodically until a definite determination is made in the process in S22.

[0085] [6] The relational constraint data corresponds to relational constraint data 54b. The relational expression corresponds to equation (c1).

[0086] [7] Operation processing corresponds to operation signal output processing M24. Response processing corresponds to compensation torque calculation processing M20.

[0087] Other implementation methods

[0088] Note that this implementation can also be performed by adding the changes described below. This implementation and the following modifications can be combined, provided they do not cause any technical inconsistencies.

[0089] Simultaneous equations

[0090] -If the column axis 14 does not expand or contract, an equation with a predetermined value for the length between point A and point B can be used instead of equation Eq1.

[0091] - If the intermediate axis 18 does not expand or contract, equation Eq4 can be replaced by an equation that limits the length between point B and point C to a predetermined value.

[0092] For example, when the tilt rotation center is the center of the joint cross shaft 16c of the first universal joint 16, equations Eq1 and Eq4 cannot be used to solve the equations simultaneously. In this case, equation Eq1 can be replaced by an equation that limits the length between points A and B to a predetermined value, and equation Eq4 can be replaced by an equation that limits the length between points B and C to a predetermined value. However, it is expected that the expansion and contraction of the column shaft 14 and the intermediate shaft 18 caused by the change in tilt angle θtl can be ignored.

[0093] - In equation Eq6, a vector moving from point C to point D is used as a vector parallel to the axial direction of the pinion shaft 22, but the invention is not limited to this. For example, a vector having a direction that deviates from the axial direction of the pinion shaft 22 only by a predetermined angle β can be used. In this case, the independent variable of the cosine function of equation Eq6 should be "α²-β".

[0094] Mapping data

[0095] - The mapping data is not limited to data constrained by simultaneous equations. For example, the mapping data can be data constrained by a regression model, where the first bending angle α1 and the second bending angle α2 are input variables, and the tilt angle θtl is the output variable. That is, the mapping data can be data constrained by a learning model. Here, the regression model can be a linear regression model. Alternatively, the regression model can be a neural network. Note that the learning model should generate various tilt angles θtl, and the first bending angle α1 and the second bending angle α2 that realize the tilt angle θtl as training data.

[0096] Output axis angle variable acquisition and processing

[0097] - The output shaft angle variable acquisition process is not limited to acquiring a value calculated using the rotation angle θm of the auxiliary motor 42 as input. For example, a sensor configured to detect the rotation angle of the pinion shaft 22 can be provided, so that the output shaft angle variable acquisition process can be a process of acquiring the detected value from the sensor. Alternatively, for example, a sensor configured to detect the amount of displacement of the rack shaft 30 in the axial direction can be provided, so that the output shaft angle variable acquisition process can be a process of acquiring a value calculated using the detected value from the sensor as input.

[0098] relational expression

[0099] The relation is not limited to one that uses the pinion angle θp as the independent variable and the control angle θh as the output variable. For example, the relation could use the control angle θh as the independent variable and the pinion angle θp as the output variable. The relation does not necessarily have to be in the form of a function. For example, the relation could be one in which the values ​​obtained by calculating the pinion angle θp and the control angle θh are converted to constants, such as "0".

[0100] Bending Angle Acquisition and Processing

[0101] - The bending angle acquisition process is not limited to the least squares method using relation (c1). For example, the bending angle acquisition process can be a regression model where the control angle θh and pinion angle θp are taken as inputs, and the first bending angle α1, the second bending angle α2, and the difference angle variable ψ are taken as outputs. Here, the regression model as the learning model can be a linear regression model. Alternatively, the regression model can be a neural network. The learning of the regression model can be achieved using the control angle θh and pinion angle θp, as well as the values ​​of the first bending angle α1, the second bending angle α2, and the difference angle variable ψ measured in response to the control angle θh and pinion angle θp, as training data.

[0102] In the case where the intermediate axis 18 does not have a phase difference ε, or where the tolerance of the phase difference ε can be ignored, the angle ξ formed in this paper can be the difference angle variable as the estimation target.

[0103] - In the case where the intermediate shaft 18 is not configured with a phase difference ε, or where the tolerance of the phase difference ε can be ignored, and where the axial direction of the column shaft 14, the axial direction of the intermediate shaft 18 and the axial direction of the pinion shaft 22 are parallel to a plane, the difference angle variable ψ does not need to be estimated.

[0104] Reflection and processing

[0105] - The reaction processing is not limited to the processing including the compensation torque calculation processing M20. For example, in the auxiliary torque calculation processing M22, it is possible to implement a process that calculates the auxiliary torque Ta using the control angle θh, the control torque Th, and the tilt angle θtl as inputs. In this case, the reaction processing can be configured by the auxiliary torque calculation processing M22.

[0106] The processing is not limited to the processing of the gravitational component in the compensation control torque Th.

[0107] Manipulating computing devices

[0108] - The control device 50 is not limited to a device that includes a PU 52 and a storage device 54 and is configured to perform software processing. For example, the control device 50 may include dedicated hardware circuitry (e.g., an ASIC, etc.) configured to cause at least a portion of the processing performed by software processing in the above embodiments to be performed by hardware processing. That is, the manipulating computing device may have any of the following configurations (a) to (c).

[0109] (a) The operating computing device includes a processing device configured to perform all of the above-described processes according to a program, and a program storage device such as a ROM storing a program.

[0110] (b) The manipulating computing device includes a processing device configured to perform a portion of the above-described processing according to a program, a program storage device, and dedicated hardware circuitry configured to perform the remaining processing.

[0111] (c) The manipulation computing device includes dedicated hardware circuitry configured to perform all of the processes described above.

[0112] Here, multiple software processing circuits, including processing means and program storage means, or multiple dedicated hardware circuits, can be provided. That is, the processing can be performed by a processing circuit that includes at least one of one or more software processing circuits and one or more dedicated hardware circuits.

[0113] Operating device

[0114] - The operating device is not limited to a configuration in which the rotation axes of the rack shaft 30 and the auxiliary motor 42 are placed parallel to each other. For example, the operating device may include a second rack and pinion mechanism separated from the rack and pinion mechanism 32, so as to provide torque to the auxiliary motor 42 via the second rack and pinion mechanism.

[0115] other

[0116] The factors that change the bending angles α1 and α2 are not limited to changes in the tilt angle. For example, the use of the telescopic function can be a factor that changes the bending angles α1 and α2.

Claims

1. A control calculation device for calculating the values ​​of state variables relating to a control device (10), the control device (10) comprising a steering wheel (12), an input shaft, an intermediate shaft (18), an output shaft, a first universal joint (16), a second universal joint (20), and a steering wheel (36), the input shaft being connected to the steering wheel (12), the first universal joint (16) being a component connecting the input shaft and the intermediate shaft (18), the second universal joint (20) being a component connecting the intermediate shaft (18) and the output shaft, the steering wheel (36) being configured to receive a control torque input to the steering wheel (12) via the input shaft, the intermediate shaft (18), and the output shaft, the control calculation device being characterized in that it comprises: Storage device; as well as Actuating device, wherein, The storage device stores mapping data, which is data that defines the output tilt angle by taking a first bending angle and a second bending angle as inputs. The first bending angle is the angle formed between the input shaft and the intermediate shaft (18); The second bending angle is the angle formed between the output shaft and the intermediate shaft (18); The actuator is configured to perform bending angle acquisition processing and tilt angle calculation processing; The bending angle acquisition process is the process of acquiring the first bending angle and the second bending angle; The tilt angle calculation process involves inputting the first bending angle and the second bending angle into the mapping to calculate the tilt angle; and The tilt angle is a variable indicating the angle formed between the axial direction of the input shaft and the reference direction. The mapping data includes data indicating parallel vector components parallel to the reference direction; The mapping includes position coordinate output mapping, vector output mapping, and tilt angle output mapping; The position coordinate output mapping is a mapping between the position coordinates of the steering wheel side end and the rotation center of the first universal joint (16) based on the first bending angle and the second bending angle. The vector output mapping is a mapping of the input axis vector that outputs the vector determined based on the position of the rotation center of the first universal joint (16) and the side end of the steering wheel; The tilt angle output mapping is a mapping that outputs the tilt angle using the input axis vector and the parallel vector component as input; and The steering wheel side end is the steering wheel side end of the two ends of the input shaft.

2. The manipulation computing device according to claim 1, characterized in that, The position coordinate output mapping is a mapping that outputs the position coordinates as the solution to a simultaneous equation; The simultaneous equations include the first bending angle relationship and the second bending angle relationship; The first bending angle relationship is an expression indicating the relationship between the first bending angle and the vector determined by the rotation center of the first universal joint (16) and the steering wheel side end, and the vector determined by the rotation center of the first universal joint (16) and the rotation center of the second universal joint (20); and The second bending angle relationship is an expression indicating the relationship between the second bending angle and the inner product between the vector determined by the rotation center of the first universal joint (16) and the rotation center of the second universal joint (20) and a predetermined vector.

3. The manipulation computing device according to claim 2, characterized in that, The axial direction of the input shaft can be changed by rotating the input shaft around a predetermined portion that is different from the first universal joint (16) as the center of rotation; The intermediate shaft can expand and contract by changing the axial direction of the input shaft; The mapping data includes the position coordinates of the predetermined portion; and The simultaneous equations include an equation representing the distance between the predetermined portion and the rotation center of the first universal joint (16).

4. The manipulation computing device according to any one of claims 1 to 3, characterized in that, The actuator is configured to further perform manipulation angle variable acquisition processing and output shaft angle variable acquisition processing; The control angle variable acquisition process is a process of acquiring the value of the control angle variable, which is a variable indicating the rotation angle of the steering wheel (12); The output shaft angle variable acquisition process is the process of acquiring the value of the output shaft angle variable, which is a variable indicating the rotation angle of the output shaft; and The bending angle acquisition process is a process of calculating the first bending angle and the second bending angle by using the values ​​of the manipulation angle variable and the output shaft angle variable as input.

5. The manipulation computing device according to claim 4, characterized in that, The manipulation angle variable acquisition process includes the process of acquiring different values ​​of the manipulation angle variable; The output shaft angle variable acquisition process includes the process of acquiring the value of the output shaft angle variable, and the value of the output shaft angle variable is synchronized with different values ​​of the control angle variable; Relationship-defined data is stored in the storage device; The relational constraint data is data that defines the relational expression; The relationship is a formula that defines the relationship between the values ​​of the control angle variable and the output shaft angle variable and the first bend angle and the second bend angle; and The bending angle acquisition process includes calculating the first bending angle and the second bending angle by inputting different values ​​of the control angle variable and the output shaft angle variable into the relational expression using the least squares method. The value of the output shaft angle variable is synchronized with the different values ​​of the control angle variable.

6. The manipulation computing device according to any one of claims 1 to 3, characterized in that, The control device includes an actuator configured to generate power to steer the steering wheel; The control device is configured to perform operation processing and response processing; The operation process is the process of operating the actuator in response to the operation of the steering wheel; and The reflection process is the process of reflecting the tilt angle in the operation of the actuator.

7. The manipulation computing device according to claim 4, characterized in that, The control device includes an actuator configured to generate power to steer the steering wheel; The control device is configured to perform operation processing and response processing; The operation process is the process of operating the actuator in response to the operation of the steering wheel; and The reflection process is the process of reflecting the tilt angle in the operation of the actuator.

8. The manipulation computing device according to claim 5, characterized in that, The control device includes an actuator configured to generate power to steer the steering wheel; The control device is configured to perform operation processing and response processing; The operation process is the process of operating the actuator in response to the operation of the steering wheel; and The reflection process is the process of reflecting the tilt angle in the operation of the actuator.

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