JP2014040160A - Steering control device of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve steering feeling.SOLUTION: A steering control device of a vehicle includes: a steering member for an operator; a motor 26 that applies an assist torque Ta for steering; and a control section 100 that controls the motor 26 so as to apply a target steering reaction force Tid to the steering member. The control section 100 sets the target steering reaction force Tid on the basis of a first element based on a steering angle MA and a second element based on a steering torque Ts applied by the operator and the assist torque Ta. The control section 100 may set the target steering reaction force Tid on the basis of a first target steering reaction force Tid1 corresponding to an input including the steering angle MA and a vehicle velocity V and a second target steering reaction force Tid2 corresponding to an input including the steering torque Ts and the assist torque Ta.

Description

  The present invention relates to a vehicle steering control device.

  2. Description of the Related Art Electric power steering (EPS) is known that performs reaction force control by setting a target steering reaction force based on a steering angle and a vehicle speed (see, for example, Patent Document 1). In addition, Patent Documents 2 and 3 exist as prior art documents related to the present invention.

US Patent No. 5,1989,811 JP 2012-17062 A JP 2012-11861 A

  Actually, there is room for improvement in the steering feeling in such a steering apparatus.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an improved steering feeling.

  A vehicle steering control device according to an aspect of the present invention controls a steering member for a driver, a motor that provides auxiliary power for steering, and the motor so that a target steering reaction force is applied to the steering member. A control unit configured to set the target steering reaction force based on a first element based on a steering angle and a second element based on a steering torque by the driver and the auxiliary power.

  According to this aspect, in addition to the steering angle, the torque acting for steering is also reflected in the setting of the target steering reaction force. In this way, the range of adjustment of the steering feeling can be widened by adding the torque. As a result, an improved steering feeling can be provided.

  The control unit may calculate a variable composed of the first element and the second element in order to set the target steering reaction force. The variable is determined according to the vehicle speed in the intermediate vehicle speed range between the low speed range and the high speed range, and the second element is dominant in the low speed range including the stop, the first element is dominant in the high speed range. The distribution may include the first element and the second element.

  For example, the driver may release his / her hand from the steering member while being somewhat steered while the vehicle is stopped. At this time, if the motor output corresponding to the steering angle is continued before the release and during the release, there is a possibility that a return operation unintended by the driver is caused to the steering member during the release by the continuation of the output. However, according to the above aspect, in calculating the target steering reaction force while the vehicle is stopped, the second element based on torque is mainly used instead of the first element based on the steering angle. By considering the torque, it is possible to incorporate the influence of the hand-off operation into the reaction force control, which helps to improve the steering feeling.

  Further, according to the above aspect, the variable serving as a basis for setting the target steering reaction force is set so that the first element and the second element are combined in the intermediate vehicle speed range and the first element is mainly used in the high speed range. Distribution of the 1st element and 2nd element which comprise is adjusted according to vehicle speed. As a result, it is possible to reduce excessive fluctuations in the target steering reaction force with respect to changes in the vehicle speed.

  Note that the second element is dominant in the low speed range means that the ratio of the second element in the variable in the low speed range is equal to the maximum value of the ratio of the second element in the variable in the medium speed range, or Say bigger than that. This variable may coincide with the second element in the low speed range. The fact that the first element is dominant in the high speed range means that the ratio of the first element to the variable in the high speed range is equal to or greater than the maximum value of the ratio of the first element to the variable in the medium speed range. Say big. This variable may match the first element in the high speed range. In the medium speed range, the ratio of the second element to this variable is determined to decrease continuously or stepwise as the vehicle speed increases (in other words, in the medium speed range, the first element for this variable The ratio is determined to increase continuously or stepwise as the vehicle speed increases).

  The control unit includes: a first temporary target steering reaction force corresponding to an input including the steering angle and a vehicle speed; and a second temporary target steering reaction force corresponding to an input including the steering torque and the auxiliary power. The target steering reaction force may be set based on this.

  According to this aspect, the first temporary target steering reaction force is used as the first element, and the second temporary target steering reaction force is used as the second element. The configuration of such target steering reaction force setting is realized by, for example, diverting the calculation of the existing target steering reaction force for the first temporary target steering reaction force and adding the calculation of the second temporary target steering reaction force. can do. Therefore, the present invention can be applied to existing steering control devices relatively easily.

  The control unit calculates a combined steering angle composed of the measured first steering angle and a second steering angle estimated based on the steering torque and the auxiliary power, and the combined steering angle and vehicle speed are calculated. The target steering reaction force may be set based on the above.

  According to this aspect, the first steering angle is used as the first element, and the second steering angle is used as the second element. In this case, for example, the target steering reaction force can be set using the combined steering angle of the first steering angle and the second steering angle as an input to the existing target steering reaction force calculation. Since only one calculation for setting the target steering reaction force is required, a memory for calculation can be saved.

  Note that any combination of the above-described constituent elements and the constituent elements and expressions of the present invention replaced with each other among methods, apparatuses, systems, programs, and the like are also effective as an aspect of the present invention.

  According to the present invention, an improved steering feeling can be provided.

It is a figure which shows the outline of the whole structure of the steering control apparatus which concerns on one embodiment of this invention. It is a block diagram for demonstrating the structure for reaction force control which concerns on one embodiment of this invention. It is a graph which illustrates the coefficient used for the setting of the target steering reaction force concerning an embodiment of the invention. It is a block diagram for demonstrating the structure for reaction force control which concerns on other one Embodiment of this invention. 6 is a graph illustrating coefficients used for setting a target steering reaction force according to another embodiment of the present invention. 6 is a graph illustrating coefficients used for setting a target steering reaction force according to another embodiment of the present invention.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate.

  FIG. 1 is a diagram showing an outline of the overall configuration of a steering control device 10 according to an embodiment of the present invention. The steering control device 10 is an electric power steering device for a vehicle such as a passenger car. The steering control device 10 includes a steering member 12 for an operation by a driver, and a steering mechanism 16 that mechanically connects the steering member 12 and a wheel 14 to be steered. The steering member 12 is, for example, a steering wheel that is attached to the steering mechanism 16 so that the driver can rotate the steering member 12.

  The steering mechanism 16 includes a steering column 18, a steering shaft 20, a gear mechanism 22, and a link mechanism 24. A steering member 12 is provided at one end of the steering column 18. The steering mechanism 16 is configured such that an operation on the steering member 12 is transmitted to the gear mechanism 22 and the link mechanism 24 via the steering column 18 and the steering shaft 20, and the wheel 14 is finally steered.

  The steering control device 10 includes an auxiliary power source, such as a motor 26, configured to supply auxiliary power for steering. The motor 26 is provided in the steering column 18 and is configured to apply assist torque to the steering shaft 20. For example, the motor 26 includes an electric motor and a speed reducer for transmitting the output of the motor to the steering shaft 20. The steering control device 10 is not limited to such a column assist type electric power steering device, and may be a steering control device having any other form.

  The steering control device 10 includes a sensor for measuring an amount related to steering control. The steering control device 10 includes, for example, a displacement sensor for measuring an operation displacement amount by a driver, for example, a steering angle sensor 28, and a force sensor for measuring an operation force by the driver, for example, a steering torque sensor 30. . The steering angle sensor 28 is attached to, for example, a rotating portion that connects the steering member 12 and the steering column 18 and is configured to measure the steering angle by the driver. The steering torque sensor 30 is built in, for example, the steering column 18 and is configured to measure the steering torque by the driver.

  The steering control device 10 includes a vehicle speed sensor 32 for measuring the traveling speed of the vehicle. These various sensors do not need to be provided exclusively for the steering control device 10, and may be shared with other devices constituting the vehicle.

  The steering control device 10 includes a control unit 100 for controlling auxiliary power. The control part 100 can employ | adopt arbitrary structures as an electronic control unit (ECU) known in this field | area. For example, the control unit 100 is realized as hardware by a CPU, memory, or other LSI of an arbitrary computer, or as software by a program loaded in the memory.

  For example, the control unit 100 is configured to execute reaction force control for controlling the motor 26 so that a target steering reaction force is applied to the steering member 12. Specifically, the control unit 100 gives the target steering reaction force to the steering member 12 by controlling the assist torque by the motor 26. The control unit 100 is configured to set the target steering reaction force based on the input.

  The control unit 100 is configured to receive an output signal of a sensor related to steering control through a communication circuit or a communication network. Therefore, the control unit 100 can receive a measurement signal representing the steering angle output from the steering angle sensor 28. Similarly, the control unit 100 is configured to receive a measurement signal representing the steering torque output by the steering torque sensor 30. The control unit 100 is configured to receive a measurement signal representing the vehicle speed output by the vehicle speed sensor 32. The control unit 100 can use the received signal as an input for setting the target steering reaction force.

  The control unit 100 is also configured to use a signal representing the assist torque of the motor 26 as an input for setting the target steering reaction force. For example, the control unit 100 includes a driver for the motor 26 and can use a command signal given to the driver to generate assist torque for setting the target steering reaction force. Alternatively, the control unit 100 may use a signal representing the assist torque generated based on the command signal to the driver for setting the target steering reaction force.

  FIG. 2 is a block diagram for explaining a configuration for reaction force control according to an embodiment of the present invention. As shown in FIG. 2, the control unit 100 includes a target setting unit 102 and an assist torque calculation unit 104.

  The target setting unit 102 is configured to set a target steering reaction force Tid. The setting of the target steering reaction force Tid is based on inputs including the steering angle MA, the vehicle speed V, the steering torque Ts, and the assist torque Ta. Among these, the steering angle MA, the vehicle speed V, and the steering torque Ts are input to the target setting unit 102 from the steering angle sensor 28, the vehicle speed sensor 32, and the steering torque sensor 30, respectively, as described above. The assist torque Ta is input from the assist torque calculation unit 104 or the motor 26 to the target setting unit 102. The target setting unit 102 is configured to output the set target steering reaction force Tid to the assist torque calculation unit 104.

  The target setting unit 102 includes a first target steering reaction force calculation unit 106, a second target steering reaction force calculation unit 108, and an output arbitration unit 110. The first target steering reaction force calculation unit 106 calculates a first target steering reaction force Tid1, and the second target steering reaction force calculation unit 108 calculates a second target steering reaction force Tid2. The first target steering reaction force calculation unit 106 outputs the first target steering reaction force Tid1 to the output arbitration unit 110, and the second target steering reaction force calculation unit 108 outputs the second target steering reaction force Tid2 to the output arbitration unit 110. Output to. As will be described in detail later, the output arbitration unit 110 sets the target steering reaction force Tid based on the first target steering reaction force Tid1 and the second target steering reaction force Tid2. Therefore, the first target steering reaction force Tid1 and the second target steering reaction force Tid2 can be different from the finally set target steering reaction force Tid, and thus the temporary target steering reaction force or the target steering reaction force Can be considered as candidates.

  The first target steering reaction force calculator 106 calculates a corresponding first target steering reaction force Tid1 from an input including the steering angle MA and the vehicle speed V. The correspondence between the input and the first target steering reaction force Tid1 is determined in advance as a map, for example, and this map is stored in the memory of the control unit 100 or the like. The first target steering reaction force calculation unit 106 is not limited to this, and may be configured to calculate the target steering reaction force by any existing method based on the steering angle MA.

  In an exemplary correspondence relationship between one type of input (hereinafter, sometimes referred to as “first input”, for example, steering angle MA) and the first target steering reaction force Tid1, the first input is zero. The first target steering reaction force Tid1 is also zero (for example, when the steering member 12 is in the neutral position). Further, the first input and the first target steering reaction force Tid1 are related so that the first target steering reaction force Tid1 increases as the first input (more precisely, the absolute value thereof) increases. At this time, the first input and the first target steering reaction force Tid1 are related so that the increase amount of the first target steering reaction force Tid1 with respect to the unit increase amount of the first input decreases as the first input increases. (For example, the first target steering reaction force Tid1 may be proportional to the square root of the first input).

  In order to correlate the other input (hereinafter sometimes referred to as “second input”, for example, vehicle speed V.) and the first target steering reaction force Tid1, for each divided range (for example, vehicle speed range) of the second input. A correspondence relationship (for example, a map) between the first input and the first target steering reaction force Tid1 may be determined. Alternatively, a correction coefficient for correcting the first target steering reaction force Tid1 obtained from the first input to the final first target steering reaction force Tid1 according to the second input may be determined.

  The second target steering reaction force calculator 108 calculates a corresponding second target steering reaction force Tid2 from the input including the estimated load Tx and the vehicle speed V. As will be described later, the estimated load Tx is a value representative of torque acting on the column shaft of the steering column 18. The correspondence relationship between the input and the second target steering reaction force Tid2 is determined in advance as a map, for example, and this map is stored in the memory of the control unit 100 or the like. The second target steering reaction force calculator 108 may calculate the second target steering reaction force Tid2 from only the estimated load Tx.

  The correspondence between the input to the second target steering reaction force calculation unit 108 and the second target steering reaction force Tid2 can be determined by the same rules as the first target steering reaction force calculation unit 106. For example, when the estimated load Tx is zero, the second target steering reaction force Tid2 is also zero, and the estimated load Tx and the second target steering are increased so that the second target steering reaction force Tid2 increases as the estimated load Tx increases. The reaction force Tid2 is related. Further, the increase amount of the second target steering reaction force Tid2 may gradually decrease as the estimated load Tx increases. A plurality of correspondence relationships between the estimated load Tx and the second target steering reaction force Tid2 may be determined according to the vehicle speed V.

  The target setting unit 102 includes a load estimation unit 112 for calculating the estimated load Tx. The load estimation unit 112 calculates an estimated load Tx from an input including the steering torque Ts and the assist torque Ta. The load estimating unit 112 gives the estimated load Tx to the second target steering reaction force calculating unit 108. The calculation of the estimated load Tx is based on, for example, Tx = (1 / (τs + 1)) (Ts + Ta). Here, 1 / (τs + 1) represents a low-pass filter, τ = 1 / 2πfc, and fc is a cutoff frequency of the low-pass filter. It is not conceptually essential that the load estimation unit 112 includes such a low-pass filter, but it is desirable to actually provide it.

In order to better simulate the actual situation, other torques acting on the column shaft may be considered in the calculation of the estimated load Tx. For example, the inertia torque of the motor 26 may be used for calculating the estimated load Tx. In that case, the estimated load Tx is Tx = (1 / (τs + 1)) (Ts + Ta−I _c α _c ). Here, I _c represents the motor inertia in terms of column axis, and α _c represents the motor rotation angular acceleration in terms of column axis.

  The output arbitration unit 110 is configured to determine a target steering reaction force Tid that is finally set. The output arbitration unit 110 calculates a variable X in order to set the target steering reaction force Tid. The variable X includes a first target steering reaction force Tid1 and a second target steering reaction force Tid2. The variable X is, for example, X = K1 (V) Tid1 + (1−K1 (V)) Tid2. Here, K1 (V) is a coefficient determined according to the vehicle speed V. In the present embodiment, this variable X is used as the target steering reaction force Tid. Therefore, the output arbitration unit 110 outputs the target steering reaction force Tid. That is, Tid = K1 (V) Tid1 + (1-K1 (V)) Tid2.

  The coefficient K1 (V) takes a minimum value in the low speed range Va and takes a maximum value in the high speed range Vc so that the coefficient K1 (V) increases continuously or stepwise at least in the medium speed range Vb as the vehicle speed V increases. It has been established. The low speed range Va, the medium speed range Vb, and the high speed range Vc are determined so as not to overlap each other. In this way, the coefficient K1 (V) gives a weighting coefficient for combining the first target steering reaction force Tid1 and the second target steering reaction force Tid2 in accordance with the vehicle speed V.

  The low speed range Va includes a stop, and an upper limit thereof (that is, a lower limit of the medium speed range Vb) is determined to include a low speed travel that is not regarded as a stop. The medium speed range Vb is determined to have a sufficient width as a buffer area for switching the coefficient K1 (V) between the low speed range Va and the high speed range Vc. For example, the upper limit of the low speed range Va is 5 km / h, and the upper limit of the medium speed range Vb is 20 km / h. In this way, the second target steering reaction force Tid2 is reflected in the setting of the target steering reaction force Tid in a speed range that is not limited to when the vehicle is stopped. By making the middle speed range a buffer area, the change in the target steering reaction force Tid can be made smooth from low speed to high speed. This may also contribute to an improvement in steering feeling. The low speed range Va may be limited to an extremely low speed range (for example, less than 2 km / h) that is substantially regarded as a stop.

  FIG. 3 shows an example of the coefficient K1 (V). As shown in FIG. 3, the coefficient K1 (V) is, for example, a constant value in the low speed range Va and the high speed range Vc, is the minimum value zero in the low speed range Va, and is equal to the maximum value 1 in the high speed range Vc. In the medium speed range Vb of the low speed range Va and the high speed range Vc, it is determined to increase linearly from the minimum value zero to the maximum value 1 as the vehicle speed V increases.

  Therefore, when the coefficient K1 (V) illustrated in FIG. 3 is used, the target steering reaction force Tid matches the second target steering reaction force Tid2 in the low speed range Va, and the first target steering reaction force in the high speed range Vc. It corresponds to the force Tid1. In the medium speed range Vb, as the vehicle speed V increases, the ratio of the second target steering reaction force Tid2 to the target steering reaction force Tid decreases (that is, the ratio of the first target steering reaction force Tid1 to the target steering reaction force Tid). Becomes larger).

  The assist torque calculation unit 104 calculates the assist torque Ta based on the input including the target steering reaction force Tid and the steering torque Ts. The assist torque calculation unit 104 includes a difference generation unit 114 and a servo controller 116. The difference generation unit 114 generates a value Tid−Ts obtained by subtracting the steering torque Ts from the target steering reaction force Tid, and gives the value to the servo controller 116. The servo controller 116 obtains the assist torque Ta from the difference Tid−Ts by any known method including, for example, PID control so that the target steering reaction force Tid is realized. In this way, the control unit 100 is configured to calculate the assist torque Ta of the motor 26 based on the set target steering reaction force Tid. The control unit 100 outputs assist torque Ta to the motor 26. Further, the assist torque calculation unit 104 outputs the assist torque Ta to the load estimation unit 112 of the target setting unit 102.

  The operation of the steering control device 10 configured as described above will be described. First, when the driver operates the steering member 12, information indicating the operation (measured values of the steering angle MA and steering torque Ts) and the measured value of the vehicle speed V are input to the control unit 100. The control unit 100 obtains the estimated load Tx using the assist torque Ta obtained as a result of the previous control calculation. The control unit 100 calculates two temporary target steering reaction forces Tid1 and Tid2 in parallel based on the input measurement value and the estimated load Tx. The control unit 100 synthesizes these temporary target steering reaction forces Tid1, Tid2 according to the vehicle speed V, determines the final target steering reaction force Tid, and based on the target steering reaction force Tid, the present assist torque Ta Is calculated. The motor 26 is controlled according to the assist torque Ta thus obtained. Thus, the electric power steering in which the set target steering reaction force Tid is applied to the steering member 12 is provided.

  According to the present embodiment, the target steering reaction force Tid when the vehicle is stopped is not the first target steering reaction force Tid1 based on the steering angle MA and the vehicle speed V, but the second target steering reaction force based on the steering torque Ts and the assist torque Ta. Force Tid2. Instead, if the first target steering reaction force Tid1 is used, when the driver releases his hand from the steering member 12 while steering, the motor 26 operates by the target steering reaction force Tid corresponding to the steering angle MA, There is a possibility that the steering member 12 may be returned to the neutral position during release. However, in the present embodiment, the estimated load Tx acting on the column shaft is taken into the reaction force control by using the second target steering reaction force Tid2. In this way, it is possible to incorporate the influence of the let-off operation into the reaction force control, which leads to an improvement in steering feeling when the vehicle is stopped.

  Further, in a typical method of selectively switching the setting of the target steering reaction force Tid depending on the situation (for example, the vehicle speed V), the target steering reaction force Tid can generally differ between one setting and the other setting at the time of switching. Therefore, the target steering reaction force Tid fluctuates discontinuously due to the switching itself, which may affect the steering feeling. In contrast, according to the present embodiment, one target steering reaction force Tid composed of two types of elements is continuously used during the steering control. In the present embodiment, two types of elements are incorporated in the setting of the target steering reaction force Tid in the form of distribution adjustment instead of selective switching. This embodiment is useful for improving the steering feeling in that discontinuous setting switching is not required.

  The steering control device 10 according to an aspect of the present invention can also be expressed as follows. The steering control device 10 includes target steering reaction force setting means (for example, a target setting unit 102) that sets a target steering reaction force Tid to be applied to the steering member 12, and generates a motor so that the target steering reaction force Tid is applied. Reaction force control for controlling torque (for example, assist torque Ta) is performed. The target steering reaction force setting means is acquired based on the first steering load index acquired based on the steering angle MA and the vehicle speed V, the steering torque Ts acting on the steering member 12, and the motor-generated torque. A target steering reaction force Tid is set based on the second steering load index. The first steering load index is, for example, the first target steering reaction force Tid1, and the second steering load index is, for example, the second target steering reaction force Tid2. If it does in this way, the steering feeling at the time of a vehicle stop can be improved.

  Next, a steering control device 10 according to another embodiment of the present invention will be described with reference to FIGS. 4 to 6. This embodiment is the same as the above-described embodiment described with reference to FIGS. 1 to 3 except for the configuration of the target setting unit 102 of the control unit 100. Therefore, in the following description, the description of the same part is omitted as appropriate in order to avoid redundancy.

FIG. 4 is a block diagram for explaining a configuration for reaction force control according to another embodiment of the present invention. The target setting unit 102 shown in FIG. 4 includes a single target steering reaction force calculation unit 120, unlike the configuration shown in FIG. The target steering reaction force calculation unit 120 calculates a corresponding target steering reaction force Tid from an input including a composite steering angle MA ^** and a vehicle speed V, which will be described later. The correspondence between the input and the target steering reaction force Tid is determined in advance as a map, for example, as in the first target steering reaction force calculation unit 106 shown in FIG.

The target setting unit 102 includes a steering angle conversion unit 122 that calculates an estimated steering angle MA ^* estimated based on the estimated load Tx. The estimated load Tx is input from the load estimation unit 112 to the steering angle conversion unit 122. As described above, the estimated load Tx is based on at least the steering torque Ts and the assist torque Ta. Therefore, the estimated steering angle MA ^* is estimated based on at least the steering torque Ts and the assist torque Ta.

In general, there is a correlation between the load acting on the column shaft and the steering angle, and such correlation can be found and formulated, for example, empirically or experimentally. Therefore, the steering angle conversion unit 122 calculates the estimated steering angle MA ^* by, for example, MA ^* = K0 (V) Tx. Here, K0 (V) is a conversion coefficient for converting the estimated load Tx into the estimated steering angle MA ^* . As illustrated in FIG. 5, K0 (V) may be set to take a maximum value at a vehicle speed of zero, monotonously decrease as the vehicle speed V increases, and gradually approach a certain minimum value. Alternatively, the rudder angle conversion unit 122 may calculate the estimated steering angle MA ^* by MA ^* = f (V, Tx). Here, f (V, Tx) is a function having V and Tx as variables.

In addition, the target setting unit 102 includes an output arbitration unit 124 that calculates a variable X to be used for setting the target steering reaction force Tid. The variable X includes a measured steering angle MA and an estimated steering angle MA ^* based on the estimated load Tx. The variable X is, for example, X = K1 (V) MA + (1-K1 (V)) MA ^* . K1 (V) is a coefficient determined according to the vehicle speed V, and is illustrated in FIG. In the present embodiment, this variable X is used as the composite steering angle MA ^** . Therefore, the output arbitration unit 124 generates the composite steering angle MA ^** . That is, MA ^** = K1 (V) MA + (1-K1 (V)) MA ^* . The output arbitration unit 124 outputs the composite steering angle MA ^** to the target steering reaction force calculation unit 120.

As illustrated in FIG. 6, the coefficient K1 (V) has a minimum value of zero in the low speed range Va including only the vehicle speed zero, and is constant at a maximum value of 1 in the high speed range Vc. In the medium speed range Vb of the low speed range Va and the high speed range Vc, it is determined to increase linearly from the minimum value zero to the maximum value 1 as the vehicle speed V increases. Therefore, when this coefficient K1 (V) is used, the combined steering angle MA ^** coincides with the estimated steering angle MA ^* when the ^vehicle is stopped, and coincides with the measured steering angle MA in the high speed range Vc. In the medium speed range Vb, as the vehicle speed V increases, the ratio of the estimated steering angle MA ^* to the combined steering angle MA ^** decreases.

  Note that the coefficient K1 (V) illustrated in FIG. 6 may be used in the output arbitration unit 110 illustrated in FIG. Alternatively, the coefficient K1 (V) illustrated in FIG. 3 may be used for the output arbitration unit 124 illustrated in FIG.

The operation of the steering control device 10 configured as described above will be described. First, when the driver operates the steering member 12, information indicating the operation (measured values of the steering angle MA and steering torque Ts) and the measured value of the vehicle speed V are input to the control unit 100. The control unit 100 obtains the estimated load Tx using the assist torque Ta obtained as a result of the previous control calculation, and converts the estimated load Tx into the estimated steering angle MA ^* . The control unit 100 combines the measured steering angle MA and the estimated steering angle MA ^* according to the vehicle speed V, and determines the target steering reaction force Tid based on the combined steering angle MA ^** and the vehicle speed V. The control unit 100 calculates the current assist torque Ta based on the target steering reaction force Tid and controls the motor 26. Thus, the electric power steering in which the set target steering reaction force Tid is applied to the steering member 12 is provided. Therefore, in this case, the calculation for setting the target steering reaction force may be performed once, so that a memory for the calculation can be saved.

  As described above, the present invention has been described with reference to the above-described embodiments. However, the present invention is not limited to the above-described embodiments, and the configurations of the embodiments are appropriately combined or replaced. Those are also included in the present invention. Further, it is possible to appropriately change the combination and processing order in each embodiment based on the knowledge of those skilled in the art and to add various modifications such as various design changes to each embodiment. Embodiments to which is added can also be included in the scope of the present invention.

10 steering control device, 12 steering member, 26 motor, 100 control unit, MA measurement steering angle, MA ^* estimated steering angle, MA ^** combined steering angle, Tid target steering reaction force, Tid1 first target steering reaction force, Tid2 first 2 Target steering reaction force, X variable.

Claims (4)

A steering member for the driver;
A motor for providing auxiliary power for steering;
A control unit for controlling the motor so that a target steering reaction force is applied to the steering member,
The control unit sets the target steering reaction force based on a first element based on a steering angle and a second element based on a steering torque by the driver and the auxiliary power. apparatus. The control unit calculates a variable composed of the first element and the second element in order to set the target steering reaction force,
The variable is determined according to the vehicle speed in the intermediate vehicle speed range between the low speed range and the high speed range, and the second element is dominant in the low speed range including the stop, the first element is dominant in the high speed range. The vehicle steering control device according to claim 1, wherein the steering control device is configured to include the first element and the second element in distribution.   The control unit includes: a first temporary target steering reaction force corresponding to an input including the steering angle and a vehicle speed; and a second temporary target steering reaction force corresponding to an input including the steering torque and the auxiliary power. 3. The vehicle steering control device according to claim 1, wherein the target steering reaction force is set based on the target steering reaction force.   The control unit calculates a combined steering angle composed of the measured first steering angle and a second steering angle estimated based on the steering torque and the auxiliary power, and the combined steering angle and vehicle speed are calculated. The vehicle steering control device according to claim 1, wherein the target steering reaction force is set based on the vehicle steering force.

Images