JP7283251B2 - Control device - Google Patents

Description

The present invention relates to a control device applied to a vehicle braking device.

Patent Literature 1 discloses a brake wear estimating device that detects the temperature of brake wear members such as brake discs and brake pads using a temperature sensor and estimates the amount of wear of the brake wear members based on the temperature. .

Patent Literature 2 discloses a temperature estimating device that estimates the temperature of a brake pad using a temperature sensor.

JP 2007-253878 A JP 2009-19690 A

As a result of various experiments and simulations, the inventors of the present invention have found that when the NAO material manufactured by using non-metallic fibers as a reinforcing material is adopted for the brake pad, the brake disc as shown in FIG. It was found that the wear of the brake pads remarkably progresses when the temperature exceeds a certain threshold. FIG. 10 shows the threshold as the wear acceleration temperature Tth1. Neither Patent Document 1 nor Patent Document 2 discloses or suggests a wear accelerating temperature.

A control device for solving the above problems is a control device applied to a vehicle equipped with a braking mechanism that applies a braking force to the vehicle by pressing a friction material, which is an NAO material, against a rotating body that rotates integrally with a wheel. , a derivation unit that performs a temperature derivation process for deriving the temperature of the rotating body, and a temperature that is a boundary between a temperature range in which wear of the friction material is difficult to progress and a temperature range in which wear is likely to progress, is set as a threshold, and the rotation The gist of the present invention is to provide a determination unit that performs determination processing to determine whether or not the temperature of the body is higher than the threshold.

In the above configuration, it is determined whether or not the temperature of the rotating body is higher than the threshold. This makes it possible to detect accelerated wear of the friction material when the temperature of the rotating body is rising.

1 is a block diagram showing a control device according to a first embodiment and a vehicle to which the control device is applied; FIG. FIG. 4 is a diagram showing changes in vehicle speed when a braking force is applied to the vehicle, and explaining derivation of the temperature of the brake disc by the control device; 4 is a flowchart showing the flow of processing when the control device executes temperature derivation processing; 4 is a flowchart showing temperature derivation processing executed by the control device; 4 is a flowchart showing temperature derivation processing executed by the control device; 4 is a flowchart showing temperature derivation processing executed by the control device; 4 is a flowchart showing the flow of processing when the same control device executes determination processing; FIG. 5 is a diagram showing processing results when temperature derivation processing and determination processing are repeatedly executed; 9 is a flow chart showing the flow of processing when the control device of the second embodiment executes temperature derivation processing; FIG. 4 is a graph showing the relationship between the degree of wear of friction material of the braking mechanism and the temperature of the rotating body;

(First embodiment)
A first embodiment of the control device will be described below with reference to FIGS. 1 to 8 and 10. FIG.

FIG. 1 shows a control device 10 and a vehicle 90 controlled by the control device 10 .
The vehicle 90 has a start switch 91 for the vehicle 90 . The operating state of the start switch 91 is input to the control device 10 . Control device 10 permits driving of the power source of vehicle 90 or stops driving the power source. Hereinafter, the state in which driving of the power source is permitted is referred to as an operating state IGon. A state in which driving of the power source is stopped is referred to as a stopped state IGoff. A starting switch 91 switches between an operating state IGon and a stopped state IGoff.

Vehicle 90 includes a braking device 70 . The braking device 70 has a braking actuator 71 and a braking mechanism 73 . The brake actuator 71 includes, for example, an ABS (Antilock Brake System) unit, an ESC (Electronic Stability Control) unit as a skid prevention mechanism, a master cylinder, a negative pressure booster, and the like. A braking mechanism 73 is provided for each wheel of the vehicle 90 . The braking mechanism 73 is a disc brake and includes a brake disc 75 as a rotating body, a pad 76 as a friction material, and a wheel cylinder 74 . The pad 76 is a so-called NAO material manufactured using phenolic resin as a binding material and non-metallic fibers as a reinforcing material. The brake disc 75 is a disk that rotates together with the wheel. Brake disc 75 is made of cast iron, for example.

In the braking device 70 , when the brake fluid is supplied to the wheel cylinder 74 and the fluid pressure inside the wheel cylinder 74 increases, the pad 76 approaches and presses against the brake disc 75 . Braking force is applied to the vehicle 90 by creating friction between the pads 76 and the brake discs 75 . In the braking device 70, the higher the hydraulic pressure in the wheel cylinder 74, the greater the braking force applied to the vehicle 90.

Brake fluid is supplied to the wheel cylinder 74 through the brake actuator 71 . When the brake pedal 93 of the vehicle 90 is operated, brake fluid is supplied from the brake actuator 71 to the brake mechanism 73 . As the amount of operation of the brake pedal 93 increases, more brake fluid is supplied to the braking mechanism 73 .

The vehicle 90 is equipped with a notification device 92 . The notification device 92 is controlled by commands from the control device 10 . The notification device 92 has a function of notifying the occupants of the vehicle 90 of the information output by the control device 10 . For example, the notification device 92 has a warning light, a speaker, a display, or the like.

Vehicle 90 includes various sensors. FIG. 1 shows a wheel speed sensor 82 and a brake pedal sensor 81 as examples of various sensors. As shown in FIG. 1 , detection signals from various sensors provided in vehicle 90 are input to control device 10 .

As the brake pedal sensor 81, a stroke sensor that detects the amount of operation of the brake pedal 93, a rotation sensor that detects the position of the brake pedal 93, or a pedaling force sensor that detects the operating force of the brake pedal 93 can be used. can be done.

The control device 10 includes a vehicle speed calculation section 11, a brake detection section 12, and a temperature derivation section 20 as functional sections.
Vehicle speed calculation unit 11 calculates wheel speed VW based on the detection signal from wheel speed sensor 82 . A vehicle speed calculator 11 calculates a vehicle speed VS based on the wheel speed VW.

The brake detector 12 detects the operating state of the brake pedal 93 based on the detection signal from the brake pedal sensor 81 . That is, the brake detector 12 can detect that the brake pedal 93 is being operated. For example, if the brake pedal sensor 81 is a stroke sensor, the brake detector 12 detects the start of operation of the brake pedal 93 when the stroke amount changes from "0 (zero)". Then, when the stroke amount returns to "0 (zero)", the brake detection unit 12 detects the end of the operation of the brake pedal 93 .

The temperature derivation unit 20 is a derivation unit that executes temperature derivation processing for deriving an estimated temperature TE as an estimated value of the temperature of the brake disc 75 . The temperature derivation unit 20 includes an increase temperature calculation unit 21 and a cooling temperature calculation unit 22 . The temperature derivation unit 20 derives the estimated temperature TE based on the sum of the temperature increase amount ΔT calculated by the temperature increase calculation unit 21 and the cooling temperature TC calculated by the cooling temperature calculation unit 22, as will be described later.

Here, the temperature change of the brake disc 75 when the application of the braking force by the braking mechanism 73 is started will be described with reference to FIG. FIG. 2 is an example showing the state of the vehicle 90 that changes due to the start of application of the braking force as the vehicle speed VS.

In the example shown in FIG. 2, braking is started at timing t1 and the vehicle speed VS begins to decrease. Braking ends at timing t2. Here, the vehicle speed VS becomes "0 (zero)" at timing t2. After timing t2, the vehicle speed VS begins to increase. After timing t3, the change in the vehicle speed VS becomes small and the vehicle speed VS is maintained. At timing t4, braking is started again, so the vehicle speed VS decreases.

The pad 76 of the braking mechanism 73 is pressed against the brake disc 75 from timing t1 to timing t2. The temperature of the brake disc 75 rises due to the friction caused by the pressure. Hereinafter, a period during which the temperature of the brake disc 75 rises due to friction due to pressing is referred to as a deceleration period.

In the example shown in FIG. 2, the pad 76 is not pressed against the brake disc 75 during the period from timing t2 to timing t4. However, in the braking mechanism 73 which is a disc brake, the pad 76 may slightly contact the brake disc 75 even when the pad 76 is not pressed against the brake disc 75 . When the pad 76 is in contact with the brake disc 75, drag torque is generated as the wheel rotates. When drag torque is generated in this way, the temperature of the brake disc 75 rises due to friction.

After the deceleration period, during the period from timing t2 to timing t3 when the vehicle 90 is accelerating, if the pad 76 is in slight contact with the brake disc 75, the drag torque is generated. The temperature of the brake disc 75 rises. Hereinafter, a period during which the vehicle 90 is accelerating, such as the period from timing t2 to timing t3, is referred to as an acceleration period.

Even in the period from timing t3 to timing t4 when the vehicle speed VS is constant, if the pad 76 is in slight contact with the brake disc 75, the brake disc 75 is affected by the drag torque as in the acceleration period. Temperature rises. Hereinafter, a period during which the vehicle 90 is traveling at a constant speed, such as timing t3 to timing t4, is referred to as a steady period.

Further, hereinafter, the acceleration period during which the temperature of the brake disc 75 may rise due to the generation of drag torque and the steady period are collectively referred to as the drag period. The drag period can also be said to be a period in which the pad 76 is not pressed against the brake disc 75 after the deceleration period has ended.

The heat of the brake disc 75 is always released outside the brake disc 75 regardless of the deceleration period, the acceleration period, or the steady period. That is, the temperature of the brake disc 75 changes based on the relationship between the temperature rise caused by the friction generated between the pad 76 and the brake disc 75 and the temperature drop caused by heat dissipation. Therefore, by dividing the period in which the vehicle speed VS changes into a deceleration period, an acceleration period, and a steady period, it is possible to estimate the temperature change of the brake disc 75 . The control device 10 of the present embodiment calculates the temperature increase amount ΔT as the amount of increase in the temperature of the brake disc 75 in each of the deceleration period, acceleration period, and steady period, which are temperature increase calculation periods shown in FIG. . Further, the cooling temperature TC of the brake disc 75 is calculated during the cooling temperature calculation period from the start of braking to the start of the next braking. The estimated temperature TE can be derived from the temperature increase amount ΔT and the cooling temperature TC thus calculated.

In order to derive the estimated temperature TE, the temperature derivation unit 20 divides the period in which the vehicle speed VS changes into the aforementioned deceleration period, acceleration period, and steady period.
Specifically, the temperature derivation unit 20 sets the deceleration start point Ds as the start point of the deceleration period, and sets the deceleration end point De as the end point of the deceleration period. The temperature derivation unit 20 sets the deceleration start point Ds and the deceleration end point De based on the start and end of application of the braking force by the braking device 70 . For example, based on the operating state of the brake pedal 93 detected by the brake pedal sensor 81, the time when the operation of the brake pedal 93 is started is set as the deceleration start point Ds, and the time when the operation of the brake pedal 93 ends. is set as the deceleration end point De.

Furthermore, the temperature derivation unit 20 sets an acceleration start point As as the start point of the acceleration period, and sets an acceleration end point Ae as the end point of the acceleration period. Temperature derivation unit 20 sets acceleration start point As and acceleration end point Ae based on whether vehicle 90 is accelerating, for example, the magnitude of acceleration of vehicle 90 . The temperature derivation unit 20 sets the acceleration start point As when acceleration of the vehicle 90 is detected, and sets the acceleration end point Ae when the end of acceleration is detected.

In the example shown in FIG. 2, timing t1 is set as the deceleration start point Ds. A timing t2 is set as the deceleration end point De. A timing t2 is set as the acceleration start point As. A timing t3 is set as the acceleration end point Ae. Also, timing t4 is set as the deceleration start point Ds of the next cycle.

The increased temperature calculation unit 21 executes braking temperature increase calculation processing as processing for calculating the amount of increased temperature ΔT during the deceleration period. In the braking temperature increase calculation process, the increased temperature calculation unit 21 calculates the increased temperature amount ΔT as the amount of increase in the temperature of the brake disc 75 for each small period obtained by dividing the deceleration period into equal intervals.

An example of calculating the amount of temperature increase ΔT during the deceleration period will be described. Assume that the vehicle speed VS at the start of the short period is "V1" and the vehicle speed VS at the end of the short period is "V2". Assuming that all of the kinetic energy when the vehicle speed VS changes from "V1" to "V2" is converted into thermal energy, the temperature increase ΔT for one wheel in the four-wheeled vehicle 90 is expressed by the following relational expression (formula 1) can be used for calculation.

関係式（式１）において、「Ｍ」は、車両９０の質量である。「ｍ」は、ブレーキディスク７５の質量である。「ｃ」は、ブレーキディスク７５の比熱である。なお、「α」は、大気または車体等への伝熱による損失を考慮した熱損失係数αである。熱損失係数αは、実験等によって算出した値を用いることができる。「β」は、車両９０の前輪および後輪の各軸による仕事の割合を示す軸配分βである。関係式（式１）に示すように、小期間における車速ＶＳの変化量が大きいほど、算出される増加温度量ΔＴは、大きくなる。

In the relational expression (Equation 1), “M” is the mass of the vehicle 90 . "m" is the mass of the brake disc 75; "c" is the specific heat of the brake disc 75; Note that "α" is a heat loss coefficient α that considers loss due to heat transfer to the atmosphere, vehicle body, or the like. A value calculated by experiments or the like can be used as the heat loss coefficient α. “β” is a shaft distribution β that indicates the ratio of work by each shaft of the front wheels and rear wheels of the vehicle 90 . As shown in the relational expression (Equation 1), the larger the amount of change in the vehicle speed VS in the short period, the larger the calculated temperature increase ΔT.

Furthermore, the increased temperature calculation unit 21 executes an accelerated temperature rise calculation process as a process of calculating the amount of temperature increase ΔT during the acceleration period. In the acceleration temperature rise calculation process, a temperature increase amount ΔT is calculated as an amount of increase in the temperature of the brake disc 75 for each small period obtained by dividing the acceleration period into equal intervals. In the acceleration temperature rise calculation process, the amount of increase in temperature ΔT is calculated assuming that the pad 76 and the brake disc 75 are in contact with each other during the acceleration period and drag torque is always generated.

An example of calculating the amount of temperature increase ΔT during the acceleration period will be described. The amount of temperature increase ΔT for one wheel of the four-wheeled vehicle 90 can be calculated using the following relational expression (Equation 2).

関係式（式２）において、「α」は、熱損失係数αである。熱損失係数αは、実験等によって算出した値を用いることができる。「Ｎ」は、引き摺りトルクの大きさである。「Ｄ」は、車両９０の移動距離である。「Ｒ」は、車輪に取り付けられているタイヤの半径である。「ｍ」は、ブレーキディスク７５の質量である。「ｃ」は、ブレーキディスク７５の比熱である。加速期間が分割された小期間における車両９０の移動距離を「Ｄ」として用いることで、小期間における増加温度量ΔＴを算出することができる。関係式（式２）を用いて算出される増加温度量ΔＴは、移動距離が長いほど大きくなる。

In the relational expression (Equation 2), "α" is the heat loss coefficient α. A value calculated by experiments or the like can be used as the heat loss coefficient α. "N" is the magnitude of the drag torque. “D” is the distance traveled by the vehicle 90 . "R" is the radius of the tire mounted on the wheel. "m" is the mass of the brake disc 75; "c" is the specific heat of the brake disc 75; By using the travel distance of the vehicle 90 in the short periods into which the acceleration period is divided as "D", the temperature increase ΔT in the short periods can be calculated. The increased temperature amount ΔT calculated using the relational expression (Equation 2) increases as the movement distance increases.

Further, the temperature increase calculation unit 21 executes constant rate temperature increase calculation processing as processing for calculating the amount of temperature increase ΔT during the steady period. In the constant-speed temperature increase calculation process, the amount of temperature increase ΔT is calculated on the assumption that the pad 76 and the brake disc 75 are in contact with each other during the steady period and drag torque is always generated. An example of calculating the amount of increase in temperature ΔT during the steady period will be described. The amount of increase in temperature ΔT for one wheel in the four-wheeled vehicle 90 can be calculated by the above relational expression (Equation 2) by using the moving distance of the vehicle 90 in the steady period as "D".

The cooling temperature calculator 22 calculates the cooling temperature TC. The cooling temperature TC is calculated using the following relational expression (equation 3) based on the law of cooling.

関係式（式３）において、「Θ」は、ブレーキディスク７５の初期温度である。初期温度とは、冷却温度算出期間の開始時点でのブレーキディスク７５の温度である。たとえば、導出されている推定温度ＴＥを初期温度として用いることができる。また、初期温度は、常温でのブレーキディスク７５の温度として予め定められた規定の温度を設定してもよい。「θ_０」は、ブレーキディスク７５が設置されている雰囲気下の温度、すなわち雰囲気温度である。「ｔ」は、冷却温度算出期間の開始時点からの経過時間である。「ｂｖ」は、ブレーキディスク７５の伝熱の大きさを表す冷却係数ｂｖである。冷却係数ｂｖは、ブレーキディスク７５の熱伝達率とブレーキディスク７５の表面積およびブレーキディスク７５の熱容量から算出した値を設定するとよい。

In the relational expression (Equation 3), “Θ” is the initial temperature of the brake disc 75 . The initial temperature is the temperature of the brake disc 75 at the start of the cooling temperature calculation period. For example, the derived estimated temperature TE can be used as the initial temperature. Also, the initial temperature may be set to a prescribed temperature that is predetermined as the temperature of the brake disc 75 at room temperature. “θ ₀ ” is the temperature under the atmosphere in which the brake disc 75 is installed, that is, the ambient temperature. “t” is the elapsed time from the start of the cooling temperature calculation period. “bv” is a cooling coefficient bv representing the magnitude of heat transfer of the brake disc 75 . A value calculated from the heat transfer coefficient of the brake disc 75, the surface area of the brake disc 75, and the heat capacity of the brake disc 75 may be set as the cooling coefficient bv.

Further, the control device 10 includes a determination section 23 and a notification processing section 24 as functional sections.
The determination unit 23 determines whether or not the estimated temperature TE derived as the temperature of the brake disc 75 is higher than the threshold. The determination unit 23 stores three thresholds. Each threshold value is set to a value calculated in advance by experiment or the like.

The first threshold is the wear acceleration temperature Tth1. As the temperature of the brake disc 75 rises, the wear of the pad 76 progresses. FIG. 10 illustrates the relationship between the degree of wear of the pad 76 and the temperature of the brake disc 75. As shown in FIG. As shown in FIG. 10, there is a boundary temperature between a temperature range in which wear of the pad 76 is difficult to progress and a temperature range in which wear is likely to progress. When the conditions such as the wheel speed VW before braking, the wheel speed VW after braking, the road surface condition, and the vehicle characteristics are all the same, the temperature range where wear tends to progress is slightly higher than the temperature range where wear does not progress easily. The amount of wear per braking cycle tends to double or more. The temperature that is the boundary of the temperature range is stored in the determination unit 23 as the wear acceleration temperature Tth1. The wear acceleration temperature Tth1 is generally a value that is 200° C. or more higher than the temperature of the atmosphere. If the pad 76 is pressed against the brake disc 75 while the temperature of the brake disc 75 is high, the temperature of the pad 76 is likely to rise. When the temperature of the pad 76 is high, the pad 76 wears more easily than when the temperature is low due to the characteristics of the material of the pad 76 . That is, when the brake disc 75 is pressed against the pad 76 while the temperature of the brake disc 75 is higher than the wear acceleration temperature Tth1, the degree of wear of the pad 76 progresses significantly.

Depending on the materials of the pads and the brake disc, the phenomenon that the pads are more likely to wear when the pad temperature is high than when the pad temperature is low may not occur. For example, a pad using low steel material containing about 10% to about 30% steel fiber as a reinforcing material, a pad using a semi-metal material containing about 30% to about 50% steel fiber as a reinforcing material, and a pad mainly made of metal A pad using a metal material as a component shows a different tendency from the pad 76 made of NAO material. As a reference example, when a low steel material is used as a pad, when the temperature of the brake disc and the pad becomes high, the brake disc rather than the pad may be easily worn.

The second threshold is the vibration generation temperature Tth2. When the temperature of the brake disc 75 rises, a large vibration may occur when the brake disc 75 is pressed against the pad 76 under the condition that the wheel is rotating. For example, if the manner of contact between the pad 76 and the brake disc 75 changes, vibration is likely to occur. A temperature that is a boundary between a temperature range in which the vibration is unlikely to occur and a temperature range in which the vibration is likely to occur is set as the vibration generation temperature Tth2. When the temperature of brake disc 75 becomes higher than vibration generation temperature Tth2, vibration is likely to occur. Generally, the vibration generation temperature Tth2 is higher than the wear acceleration temperature Tth1.

The third threshold is the fade temperature Tth3 at which the fading phenomenon of the friction material occurs. When the temperature of the brake disc 75 rises, a fade phenomenon occurs in which the pad 76 evaporates. Generally, the fade temperature Tth3 is higher than the vibration generation temperature Tth2.

In this embodiment, the vibration generation temperature Tth2 is set as a value higher than the wear acceleration temperature Tth1, and the fade temperature Tth3 is set as a value higher than the vibration generation temperature Tth2.

The notification processing unit 24 executes notification processing for notifying the occupant of the vehicle 90 of the determination result by the determination unit 23 . In the notification process, information is transmitted to the notification device 92 connected to the control device 10 . For example, when the determination unit 23 determines that the estimated temperature TE is higher than the wear acceleration temperature Tth1, the notification processing unit 24 notifies the notification device 92 that the wear of the pads 76 or the brake discs 75 is likely to be accelerated. inform. Further, when the determination unit 23 determines that the estimated temperature TE is higher than the vibration generation temperature Tth2, the notification processing unit 24 causes the notification device 92 to notify that there is a possibility that the braking mechanism 73 will vibrate. Further, when the determination unit 23 determines that the estimated temperature TE is higher than the fade temperature Tth3, the notification processing unit 24 causes the notification device 92 to notify that the fade phenomenon may occur.

The flow of processing for executing temperature derivation processing and determination processing will be described with reference to FIGS. 3 to 7. FIG.
The processing routine shown in FIG. 3 is a processing routine for executing temperature derivation processing. This processing routine is repeatedly executed at predetermined intervals.

When this processing routine is started, first, in step S101, the temperature deriving unit 20 determines whether or not the stop state IGoff has transitioned to the operating state IGon. When the vehicle 90 is started by the starter switch 91, it is determined that the stop state IGoff has shifted to the operating state IGon. If the stop state IGoff has not transitioned to the operating state IGon (S101: NO), the process of step S101 is repeatedly executed. On the other hand, when the stop state IGoff shifts to the operating state IGon (S101: YES), the process shifts to step S102.

In step S102, the temperature derivation unit 20 determines whether or not the stop period Tioff during which the stop state IGoff was continued is longer than the prescribed period Tith. The length of the specified period Tith corresponds to the specified time. In the stopped state IGoff, no frictional heat is generated between the brake disc 75 and the pad 76, so the temperature of the brake disc 75 is naturally cooled down. That is, even if the temperature of the brake disc 75 is high immediately after the stopped state IGoff, the temperature of the brake disc 75 drops to the ambient temperature _θ0 if the stopped state IGoff continues for a long time. After that, the temperature of the brake disc 75 is kept substantially equal to the ambient temperature _θ0 . Therefore, the specified period of time Tith is set as a reference value for determining whether the temperature of the brake disc 75 has decreased to the atmospheric temperature _θ0 . If the stop period Tioff is longer than the prescribed period Tith (S102: YES), the process proceeds to step S103. At step S103, the temperature derivation unit 20 initializes the estimated temperature TE. In this embodiment, the ambient temperature _θ0 is set as the estimated temperature TE. After that, the process proceeds to step S104. At step S104, the temperature derivation unit 20 starts executing the temperature derivation process.

On the other hand, in the process of step S102, when the stop period Tioff is equal to or less than the specified period Tith (S102: NO), the process proceeds to step S104 and execution of the temperature derivation process is started. That is, execution of the temperature derivation process is started without initializing the estimated temperature TE.

When execution of the temperature derivation process is started in step S104, the process proceeds to step S105. In step S105, the temperature deriving unit 20 determines whether or not the operating state IGon has transitioned to the stopped state IGoff. When the vehicle 90 is stopped by the start switch 91, it is determined that the operating state IGon has transitioned to the stopped state IGoff. If the operating state IGon has not transitioned to the stopped state IGoff (S105: NO), the process of step S105 is repeatedly executed.

On the other hand, if the operating state IGon has transitioned to the stopped state IGoff (S105: YES), the process proceeds to step S106. In step S106, the temperature derivation unit 20 terminates execution of the temperature derivation process. After that, this processing routine ends.

The processing routine shown in FIG. 4 is a processing routine for setting the deceleration period, the acceleration period and the steady period in the temperature derivation process. Execution of this processing routine is started by the processing of step S104 in FIG. 3, and is repeatedly executed until the processing of step S106 in FIG. 3 is executed.

When this processing routine is started, first, in step S201, the temperature derivation unit 20 determines whether or not the start of braking has been detected. When the operation of the brake pedal 93 is detected by the brake detection unit 12, it is determined that the start of braking has been detected. If the start of braking has not been detected (S201: NO), the process of step S201 is repeatedly executed.

On the other hand, if the start of braking has been detected (S201: YES), the process proceeds to step S202. In step S202, the temperature derivation unit 20 sets the point of time when the determination in step S201 switches from "NO" to "YES" as the deceleration start point Ds. That is, the temperature derivation unit 20 determines that the deceleration period has started in the process of step S202. After that, the process proceeds to step S203.

At step S203, the temperature deriving unit 20 determines whether or not the end of braking has been detected. If the end of braking has not been detected (S203: NO), the process of step S203 is repeatedly executed.

On the other hand, if the end of braking has been detected (S203: YES), the process proceeds to step S204. In step S204, the temperature derivation unit 20 sets the point of time when the determination in step S203 switches from "NO" to "YES" as the deceleration end point De. That is, in the process of step S204, the temperature derivation unit 20 determines that the deceleration period has ended. After that, the process proceeds to step S205.

At step S205, the temperature derivation unit 20 determines whether the vehicle 90 is accelerating. If the vehicle 90 is accelerating (S205: YES), the process proceeds to step S206. In step S206, the temperature derivation unit 20 sets the point of time when the determination in step S205 switches from "NO" to "YES" as the acceleration start point As. That is, the temperature derivation unit 20 determines that the acceleration period has started in the process of step S206. After that, the process proceeds to step S207.

At step S207, the temperature derivation unit 20 determines whether the vehicle 90 is accelerating. That is, it is determined whether or not the acceleration has continued since the acceleration start point As was set. When the vehicle 90 is accelerating (S207: YES), it is determined that it is in the acceleration period, and the process of step S207 is repeatedly executed.

On the other hand, when the vehicle 90 is not accelerating in the process of step S207 (S207: NO), the process proceeds to step S208. In step S208, the temperature derivation unit 20 sets the point in time when the determination in step S207 switches from "YES" to "NO" as the acceleration end point Ae. That is, in the process of step S208, the temperature derivation unit 20 determines that the acceleration period has ended. After that, the process proceeds to step S209.

In step S209, the temperature derivation unit 20 determines whether or not the start of braking has been detected. If the start of braking has not been detected (S209: NO), the process proceeds to step S205 again. On the other hand, if the start of braking has been detected (S209: YES), this processing routine ends.

Further, in the process of step S205, even when the vehicle 90 is not accelerating (S205: NO), the process proceeds to step S209.
Note that if the process of step S106 in FIG. 3 is executed during execution of this process routine, the temperature derivation unit 20 sets the deceleration end point De or the acceleration end point Ae, and ends this process routine. Specifically, when the process of step S106 is executed during the deceleration period, the temperature derivation unit 20 sets the time point of executing the process of step S106 as the deceleration end point De, and ends this process routine. When the process of step S106 is executed during the acceleration period, the temperature deriving unit 20 sets the execution point of the process of step S106 as the acceleration end point Ae, and ends this process routine.

Further, when the start of braking is detected in the processing of step S209, it is determined that the start of braking has been detected in the processing of step S201 in another processing routine that is being executed in parallel (S201: YES). Execution of the process after step S202 is started.

Note that the temperature derivation unit 20 defines a period after the end of the deceleration period and not the acceleration period as the steady period. That is, the temperature derivation unit 20 determines the period during which the determination in step S205 is "NO" and the determination in step S209 is "NO" as the steady period. Thereby, the temperature derivation unit 20 divides the drag period after the end of the deceleration period into an acceleration period and a steady period.

The processing routine shown in FIG. 5 is a processing routine showing processing executed by the increased temperature calculation unit 21 in the temperature derivation processing. Execution of this processing routine is started by the processing of step S104 in FIG. 3, and is repeatedly executed until the processing of step S106 in FIG. 3 is executed.

When this processing routine is started, first, in step S301, the increased temperature calculation unit 21 determines whether or not both the deceleration start point Ds and the deceleration end point De are set. If both the deceleration start point Ds and the deceleration end point De are set (S301: YES), the process proceeds to step S302. In step S302, the increased temperature calculation unit 21 executes the braking temperature rise calculation process. That is, the amount of temperature increase ΔT during the deceleration period is calculated. After that, the process proceeds to step S303.

Here, as an example, a case where the deceleration period is divided into two will be described. The first half of the deceleration period is defined as the first deceleration period, and the second half of the deceleration period is defined as the second deceleration period. In this case, the vehicle speed VS at the deceleration start point Ds, which is the start point of the first deceleration period, is substituted for "V1" in the above relational expression (formula 1), and the vehicle speed VS at the end point of the first deceleration period is substituted by the above relational formula ( It is substituted for "V2" in Equation 1). The end point of the first deceleration period is a point between the deceleration start point Ds and the deceleration end point De. Further, the vehicle speed VS at the start point of the second deceleration period is substituted for "V1" in the above relational expression (Equation 1), and the vehicle speed VS at the deceleration end point De at the end point of the second deceleration period is assigned to the above relational expression (Equation It is substituted for “V2” in 1). The start point of the second deceleration period is the same as the end point of the first deceleration period. Then, the amount of temperature increase ΔT during the first deceleration period and the amount of temperature increase ΔT during the second deceleration period are calculated as the amount of temperature increase ΔT for each small period, and the amount of temperature increase ΔT for each small period is calculated. A value is calculated as the amount of temperature increase ΔT during the deceleration period.

On the other hand, in the process of step S301, when both the deceleration start point Ds and the deceleration end point De are not set (S301: NO), the process proceeds to step S303.
In step S303, the increased temperature calculator 21 determines whether both the acceleration start point As and the acceleration end point Ae are set. If both the acceleration start point As and the acceleration end point Ae are set (S303: YES), the process proceeds to step S304. In step S304, the increased temperature calculation unit 21 executes an accelerated temperature increase calculation process. That is, the amount of temperature increase ΔT during the acceleration period is calculated. After that, this processing routine ends.

Here, as an example, a case where the acceleration period is divided into two will be described. The first half of the acceleration period is defined as the first acceleration period, and the second half of the acceleration period is defined as the second acceleration period. The amount of temperature increase ΔT during the first acceleration period and the amount of temperature increase ΔT during the second acceleration period are calculated as the amount of temperature increase ΔT in each small period, and the total value of the amount of temperature increase ΔT in each small period is It is calculated as the amount of temperature increase ΔT during the acceleration period.

On the other hand, in the process of step S303, if both the acceleration start point As and the acceleration end point Ae are not set (S303: NO), this process routine ends.
Note that in the temperature derivation process, the increased temperature calculation unit 21 calculates the constant speed increase during the steady period during the drag period, that is, the period after the end of the deceleration period and not between the acceleration start point As and the acceleration end point Ae. Execute the temperature calculation process. The amount of temperature increase ΔT during the steady period is calculated by executing the constant rate temperature increase calculation process.

The processing routine shown in FIG. 6 is a processing routine showing processing executed by the cooling temperature calculator 22 in the temperature derivation processing. Execution of this processing routine is started by the processing of step S104 in FIG. 3, and is repeatedly executed until the processing of step S106 in FIG. 3 is executed.

When this processing routine is started, first, in step S401, the cooling temperature calculator 22 determines whether or not the start of braking has been detected. If the start of braking has not been detected (S401: NO), the process of step S401 is repeatedly executed.

On the other hand, if the start of braking has been detected (S401: YES), the process proceeds to step S402. In step S402, the cooling temperature calculation unit 22 starts executing cooling temperature calculation processing. That is, calculation of the cooling temperature TC is started. When execution of the cooling temperature calculation process is started, the process proceeds to step S403.

In step S403, the cooling temperature calculator 22 determines whether or not the start of braking has been detected. If the start of braking has not been detected (S403: NO), the process of step S403 is repeatedly executed.

On the other hand, if the start of braking has been detected (S403: YES), the process proceeds to step S404. In step S404, the cooling temperature calculation unit 22 terminates execution of the cooling temperature calculation process. That is, the calculation of the cooling temperature TC ends. After that, this processing routine ends.

Further, when the start of braking is detected in the processing of step S403, it is determined that the start of braking is detected in the processing of step S401 in another processing routine that is being executed in parallel (S401: YES). Execution of the process after step S402 is started.

The processing routine shown in FIG. 7 is a processing routine showing the flow of processing for executing determination processing. Execution of this processing routine is started by the processing of step S104 in FIG. 3, and is repeatedly executed until the processing of step S106 in FIG. 3 is executed.

When this processing routine is started, first, in step S501, the temperature deriving unit 20 derives the estimated temperature TE based on the cooling temperature TC and the amount of temperature increase ΔT. The temperature deriving unit 20 sets the temperature increase amount ΔT during the deceleration period as the first temperature increase amount, and the temperature increase amount ΔT during the acceleration period as the second temperature increase amount. Also, the increased temperature amount ΔT in the steady period is defined as the third increased temperature amount. Then, the temperature derivation unit 20 derives the estimated temperature TE based on the sum of the cooling temperature TC and the first to third temperature increases. The estimated temperature TE becomes a higher value as the sum is larger. After deriving the estimated temperature TE, the process proceeds to step S502.

In step S502, the determination unit 23 determines whether or not the estimated temperature TE is higher than the wear acceleration temperature Tth1. If the estimated temperature TE is equal to or lower than the wear acceleration temperature Tth1 (S502: NO), this processing routine is terminated.

On the other hand, if the estimated temperature TE is higher than the wear acceleration temperature Tth1 (S502: YES), the process proceeds to step S503. In step S503, the determination unit 23 performs early wear determination. After that, the process proceeds to step S504.

In step S504, the determination unit 23 determines whether or not the estimated temperature TE is higher than the vibration occurrence temperature Tth2. If the estimated temperature TE is equal to or lower than the vibration generation temperature Tth2 (S504: NO), this processing routine is terminated.

On the other hand, when estimated temperature TE is higher than vibration generation temperature Tth2 (S504: YES), the process proceeds to step S505. In step S505, the determination unit 23 performs brake vibration determination. After that, the process proceeds to step S506.

In step S506, determination unit 23 determines whether or not estimated temperature TE is higher than fade temperature Tth3. If the estimated temperature TE is equal to or lower than the fade temperature Tth3 (S506: NO), this processing routine is terminated.

On the other hand, if estimated temperature TE is higher than fade temperature Tth3 (S506: YES), the process proceeds to step S507. In step S507, the determination unit 23 determines whether the braking ability is lowered. After that, this processing routine ends.

The action and effect of this embodiment will be described.
In the control device 10, the temperature increase amount ΔT of the brake disc 75 is calculated in the temperature deriving process executed by the temperature deriving section 20 based on the conversion of kinetic energy during braking into thermal energy (S302). Further, the controller 10 calculates the amount of temperature increase ΔT due to the generation of the drag torque (S304). Further, the cooling temperature TC of the brake disc 75 is calculated based on the elapsed time t from the start of braking, the ambient temperature _θ0 , and the cooling coefficient bv of the brake disc 75 .

Then, in the temperature derivation process, the estimated temperature TE is derived as the temperature of the brake disc 75 based on the sum of the temperature increase amount ΔT calculated as described above and the cooling temperature TC (S501). That is, the temperature of the brake disc 75 can be estimated without using a sensor or the like that directly detects the temperature of the brake disc 75 .

Note that the temperature derivation unit 20 sets the deceleration period and the acceleration period (S201 to S209). This makes it possible to divide the period in which the vehicle 90 is in the operating state IGon according to the amount of increase in the temperature of the brake disc 75 .

In addition, in the control device 10, the estimated temperature TE is initialized when the specified period Tith has elapsed after shifting to the stopped state IGoff (S103). That is, the temperature derivation unit 20 determines the temperature for deriving the temperature of the brake disc 75 from the time when the operating state IGon is started to the time when the specified period Tith elapses after the operating state IGon shifts to the stopped state IGoff. It is the out-licensing period. The temperature deriving unit 20 converts the value of the held estimated temperature TE to the initial temperature Θ to calculate the cooling temperature TC. On the other hand, when the operating state IGon is resumed after the lapse of the specified period Tith from the transition to the stop state IGoff, the ambient temperature _θ0 is used as the initial temperature Θ of the brake disc 75 . Thereby, it is possible to suppress the difference between the actual temperature of the brake disc 75 and the estimated temperature TE. That is, it is possible to suppress the deterioration of the accuracy of the estimated temperature TE.

Furthermore, the determination unit 23 of the control device 10 can determine whether or not the estimated temperature TE is higher than the threshold.
FIG. 8 shows an example in which the temperature derivation process is performed seven times. As shown in FIG. 8, in the second execution period D2 and the fourth execution period D4, the estimated temperature TE is higher than the wear acceleration temperature Tth1. Therefore, the determination unit 23 determines early wear (S503). That is, according to the control device 10 , it is possible to determine an early wear state in which the wear of the pads 76 may progress significantly based on the temperature of the brake disc 75 . In this case, the occupant of the vehicle 90 can be notified that the wear of the pad 76 is likely to progress by executing the notification process.

In the fifth execution period D5, the estimated temperature TE is higher than the vibration generation temperature Tth2. Therefore, the determination unit 23 performs brake vibration determination in addition to early wear determination (S505). In this case, the occupant of the vehicle 90 can be notified that there is a possibility that the braking mechanism 73 will vibrate during braking by executing the notification process.

In the sixth execution period D6, the estimated temperature TE is higher than the fade temperature Tth3. Therefore, the determination unit 23 performs early wear determination, brake vibration determination, and braking ability deterioration determination (S507). In this case, the occupant of the vehicle 90 can be notified that the braking capability may be reduced due to the occurrence of the fade phenomenon by executing the notification process.

In the first execution period D1, the third execution period D3 and the seventh execution period D7, the estimated temperature TE is not higher than the wear acceleration temperature Tth1. Therefore, the determination unit 23 does not perform any determination.

That is, according to the determination unit 23 of the control device 10, when the temperature of the brake disc 75 rises excessively, it is possible to predict the occurrence of an abnormality that may occur due to the excessive temperature rise of the brake disc 75. FIG.

Note that the wear acceleration temperature Tth1 is generally a value that is 200° C. or more higher than the temperature of the atmosphere. Therefore, the temperature of the brake disc 75 for determining the premature wear state does not require the accuracy of detection using a sensor. That is, the premature wear state can be detected even by using the estimated temperature TE, which is the estimated value of the temperature of the brake disc 75 . The ambient temperature θ ₀ used to calculate the estimated temperature TE also does not require such accuracy as detection using a sensor.

(Second embodiment)
In the second embodiment, the process shown in FIG. 9 is executed instead of the process shown in FIG. 3 in the first embodiment. Other configurations are the same as those of the first embodiment, so description thereof will be omitted.

The processing routine shown in FIG. 9 is a processing routine for executing temperature derivation processing. This processing routine is repeatedly executed at predetermined intervals.
When this processing routine is started, first, in step S601, the temperature deriving unit 20 determines whether or not the stop state IGoff has transitioned to the operating state IGon. If the stop state IGoff has not transitioned to the operating state IGon (S601: NO), the process of step S601 is repeatedly executed. On the other hand, if the stop state IGoff has transitioned to the operating state IGon (S601: YES), the process proceeds to step S602.

In step S602, the cooling temperature calculator 22 calculates the cooling temperature during the stop period. The stop period cooling temperature is calculated based on the above relational expression (Equation 3) as the temperature of the brake disc 75 due to cooling of the brake disc 75 during the period in which the stop state IGoff is continued. For example, the cooling temperature calculator 22 acquires the period during which the stopped state IGoff has continued, and calculates the cooling temperature during the stopped period. After the stop period cooling temperature is calculated, the process proceeds to step S603.

In step S603, the temperature derivation unit 20 calibrates the estimated temperature TE. The retained estimated temperature TE is calibrated to take into account the shutdown period cooling temperature. After that, the process proceeds to step S604.

The temperature derivation process is executed by executing the processes after step S604. Note that the processes in steps S604, S605, and S606 are the same as the processes in steps S104, S105, and S106, respectively, and thus description thereof is omitted.

The action and effect of this embodiment will be described.
In the first embodiment, the estimated temperature TE is initialized when the specified period of time Tith elapses after shifting to the stopped state IGoff.

In contrast, in the second embodiment, the estimated temperature TE is calibrated by calculating the stop period cooling temperature, taking into account that the brake disc 75 is cooled during the period in which the stop state IGoff continues. be able to. Thereby, it is possible to suppress the difference between the actual temperature of the brake disc 75 and the estimated temperature TE.

In the present embodiment, when the stop state IGoff shifts to the operating state IGon, the period during which the stop state IGoff continues is acquired to calculate the stop period cooling temperature. However, the cooling temperature calculation unit 22 starts calculating the stop period cooling temperature when the operating state IGon is shifted to the stopped state IGoff, and when the stopped state IGoff is shifted to the operating state IGon, the cooling temperature calculation unit 22 calculates the stop period cooling temperature. may be terminated.

Each of the above embodiments can be implemented with the following modifications. Each of the above-described embodiments and the following modifications can be implemented in combination with each other within a technically consistent range.

- The notification device 92 of each embodiment described above has a function of notifying the occupant of the vehicle 90 of the result of executing the determination process. The notification device 92 may have a function of communicating with a data center or the like located outside the vehicle 90 . That is, it is also possible to transmit the result of executing the determination process to the outside of the vehicle 90 . In such a case, it is not necessary to perform notification processing for notifying the occupant of vehicle 90 of the result of executing the determination processing.

- In each of the above embodiments, as the determination process, it is determined whether or not the estimated temperature TE is higher than the wear acceleration temperature Tth1, which is the first threshold. Here, in general, in a vehicle, the front wheels and the rear wheels have different timings and periods in which the braking force is applied by the braking mechanism. Therefore, the detection accuracy of the early wear state may be improved by changing the determination method for the front wheels and the rear wheels. For example, wear acceleration temperature Tth1 may be set to different values for front wheels and rear wheels of vehicle 90 .

As with wear acceleration temperature Tth1, vibration generation temperature Tth2 and fade temperature Tth3 may also be set to different values for the front wheels and rear wheels of vehicle 90 . Also, each threshold can be set to a different value for each wheel.

If it is determined whether or not the estimated temperature TE is higher than the wear accelerating temperature Tth1, which is the first threshold value, as the determination process, other determination processes need not be performed. That is, if the determination unit 23 is caused to execute determination processing for determining whether the estimated temperature TE is greater than the wear acceleration temperature Tth1, determination is made to determine whether the estimated temperature TE is greater than the vibration generation temperature Tth2. It is not necessary to cause the determination unit 23 to execute the processing. Further, if the determination unit 23 is caused to execute determination processing for determining whether the estimated temperature TE is greater than the wear acceleration temperature Tth1, determination processing for determining whether the estimated temperature TE is greater than the fade temperature Tth3. may not be executed by the determination unit 23 .

In each of the above-described embodiments, the increased temperature calculation unit 21 executes the braking temperature rise calculation process to calculate the amount of increased temperature ΔT for each small period obtained by dividing the deceleration period into equal intervals. Further, the increased temperature calculation unit 21 executes the accelerated temperature increase calculation process to calculate the amount of increased temperature ΔT for each small period obtained by dividing the acceleration period into equal intervals. The number of small periods can be appropriately set for each of the deceleration period and the acceleration period.

In the constant speed temperature increase calculation process, the temperature increase calculation unit 21 calculates the amount of temperature increase ΔT for each small period obtained by dividing the steady period into equal intervals in the same manner as in the braking temperature increase calculation process or the accelerated temperature increase calculation process. may The number of small periods can be set as appropriate.

The temperature increase calculation unit 21 can also calculate the amount of temperature increase ΔT by treating the acceleration period and the steady period as one period. That is, instead of executing the accelerated temperature rise calculation process and the constant speed temperature rise calculation process, the process of calculating the amount of temperature increase ΔT during the drag period may be executed. In this process, the temperature increase amount ΔT may be calculated for each small period obtained by dividing the drag period into equal intervals, or the temperature increase amount ΔT may be calculated without dividing the drag period into a plurality of periods.

- In each of the above embodiments, the deceleration period is divided into small periods in the braking temperature rise calculation process. In the braking temperature rise calculation process, it is not necessary to divide the deceleration period into a plurality of periods. In this case, the vehicle speed VS at the deceleration start point Ds during the deceleration period is substituted for "V1" in the above relational expression (Equation 1), and the vehicle speed VS at the deceleration end point De during the deceleration period is substituted for "V2 , the temperature increase ΔT during the deceleration period can be calculated.

- In each of the above-described embodiments, the acceleration period is divided into small periods in the accelerated temperature rise calculation process. In the accelerated temperature rise calculation process, it is not necessary to divide the acceleration period into a plurality of periods.
- In each of the above-described embodiments, the temperature deriving section 20 sets the time when the operation of the brake pedal 93 ends as the deceleration end point De. Alternatively, the time when the vehicle speed VS starts to increase can be set as the deceleration end point De, or the time when the vehicle speed VS stops decreasing can be set as the deceleration end point De. Even in such a case, it is possible to set the deceleration period in the same manner as in the above embodiments.

- The control device 10 can also be applied to a vehicle 90 equipped with a regenerative braking device that applies regenerative braking force to the vehicle 90 by power generation by a generator. The amount of increased temperature ΔT in this case can be calculated by correcting the amount of increased temperature ΔT calculated by the above relational expression (Equation 1) by the regeneration ratio γ indicating the ratio of the regenerative braking force to the braking force. .

Note that when the regenerative braking force is applied by the regenerative braking device, drag torque can be generated in the same manner as in the acceleration period or the steady period. Therefore, for the estimated temperature TE when the regenerative braking force is applied, it is preferable to consider the temperature increase ΔT due to the drag torque during the period when the regenerative braking force is applied. That is, in calculating the estimated temperature TE when the regenerative braking force is applied, it is preferable to use the temperature increase amount ΔT due to the drag torque calculated by the above relational expression (Equation 2).

- In each of the above-described embodiments, a value calculated based on the characteristics of the brake disc 75 is used as the cooling coefficient bv. Here, the cooling of the brake disc 75 also changes depending on the running state of the vehicle 90 . That is, the cooling coefficient bv may adopt a value derived from an experiment so that the value varies depending on the vehicle speed VS.

- In the said 1st Embodiment, when it transfers to the driving|running state IGon from the stop state IGoff in FIG.3 S101, a process is transferred to step S102. If the processing routine shown in FIG. 3 is started when the vehicle 90 transitions from the stop state IGoff to the driving state IGon, the processing of step S101 can be omitted.

Similarly, in the second embodiment, if the processing routine shown in FIG. 9 is started when the vehicle 90 transitions from the stop state IGoff to the driving state IGon, the processing of step S601 can be omitted. can also

The temperature derivation period for deriving the temperature of the brake disc 75 may be a period from when the operating state IGon is started to when the operating state IGon is shifted to the stopped state IGoff. That is, the period during which the operating state IGon is continued may be set as the temperature derivation period. For example, the processing of step S102 in FIG. 3 may be omitted, and the processing may be shifted from step S101 to step S103 when the stop state IGoff shifts to the operating state IGon. In this case, the process of step S103 can be further omitted. That is, the estimated temperature TE may be initialized before starting the temperature derivation process, or a configuration may be adopted in which the estimated temperature TE is not initialized.

- In each of the above embodiments, a disc brake is employed as the braking mechanism 73 . As the braking mechanism 73, a drum brake that can apply a braking force by pressing a brake shoe, which is a friction material, against a drum, which is a rotating body, can be used. Even when the braking mechanism 73 is a drum brake, there is a problem that the wear of the friction material progresses remarkably when the temperature of the rotating body exceeds the threshold value, as in the case of the disc brake. Therefore, even in the control device 10 of a vehicle 90 that employs a drum brake, the same effect as in the above embodiment can be obtained by determining whether the temperature of the rotating body is higher than the wear acceleration temperature Tth1. can be done.

In each of the above-described embodiments, the period during which the brake pedal 93 is operated by the driver of the vehicle 90 is defined as the deceleration period during which the braking force is applied to the vehicle 90 by the operation of the braking mechanism 73 . However, the braking force may be applied to the vehicle 90 not only by the operation of the brake pedal 93 by the driver, but also by the operation of the braking mechanism 73 . For example, the control device 10 may activate the braking mechanism 73 . In this case, the period during which the hydraulic pressure of the wheel cylinder 74 is adjusted by driving the brake actuator 71 resulting from the input of the braking instruction to the control device 10 may be the deceleration period.

In each embodiment described above, the brake detector 12 detects the operating state of the brake pedal 93 based on the detection signal from the brake pedal sensor 81 . The operating state of the brake pedal 93 can also be detected based on detection signals from sensors other than the brake pedal sensor 81 . For example, the brake detector 12 can also detect the operating state of the brake pedal 93 based on a detection signal from a pressure sensor that detects the master cylinder hydraulic pressure. The brake detector 12 can also detect the operating state of the brake pedal 93 based on a detection signal from a pressure sensor that detects the wheel cylinder hydraulic pressure.

- In each of the above-described embodiments, the vehicle 90 to which the control device 10 is applied does not include a temperature sensor for detecting the temperature of the brake disc 75 . The control device 10 derives the estimated temperature TE as the temperature of the brake disc 75 and executes determination processing for determining whether or not the estimated temperature TE is greater than the threshold.

Vehicle 90 may include a temperature sensor that detects the temperature of brake disc 75 . The control device 10 may perform the determination process using the temperature of the brake disc 75 calculated based on the detection signal of the temperature sensor. Even with such a configuration, an excessive rise in the temperature of the brake disc 75 can be detected as in the above-described embodiment.

DESCRIPTION OF SYMBOLS 10... Control apparatus 11... Vehicle speed calculation part 12... Brake detection part 20... Temperature derivation part 21... Increased temperature calculation part 22... Cooling temperature calculation part 23... Judgment part 24... Notification processing part 70... Brake device 71 Braking actuator 73 Braking mechanism 74 Wheel cylinder 75 Brake disc 76 Pad 81 Brake pedal sensor 82 Wheel speed sensor 90 Vehicle 91 Starting switch 92 Notification device, 93... brake pedal.

Claims (3)

A control device applied to a vehicle equipped with a braking mechanism that applies a braking force to the vehicle by pressing a friction material that is an NAO material against a rotating body that rotates integrally with a wheel,
a derivation unit that performs a temperature derivation process for deriving the temperature of the rotating body;
Determination processing is performed to determine whether the temperature of the rotating body is higher than the threshold temperature, which is the boundary between the temperature range in which wear of the friction material is difficult to progress and the temperature range in which wear is likely to progress. and a determination unit for
When a braking force is applied to the vehicle by the operation of the braking mechanism, the lead-out portion
calculating an amount of increase in the temperature of the rotating body after the application of the braking force is started based on the mass of the vehicle, the vehicle speed, the mass of the rotating body, and the specific heat of the rotating body, as an increased temperature amount;
calculating a cooling temperature of the rotating body based on the elapsed time from the start of applying the braking force, the ambient temperature, and the cooling coefficient of the rotating body;
Deriving the temperature of the rotating body based on the sum of the increased temperature amount and the cooling temperature
Control device. The derivation unit is
A temperature derivation period for deriving the temperature of the rotating body is defined as a period from when the start switch of the vehicle is turned on to when a specified time elapses after the start switch is turned off,
The control device according to claim 1 , wherein the temperature of the rotor is initialized when the temperature derivation period ends. The control device according to claim 1 or 2, further comprising a notification processing unit that performs notification processing when it is determined that the temperature of the rotating body is higher than the threshold value.

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