JP2004042707A - Vehicle control device - Google Patents

Abstract

In a vehicle in which a plurality of loads including a refrigerant compressor (5) are driven by a common drive source (1) or (2), occupants are prevented from suffering from deterioration in drivability and discomfort due to shock as much as possible.
Based on the output or moment of inertia of drive sources (1) and (2), power consumption of a load excluding a compressor (5), and a scheduled change in power consumption of a compressor (5), the amount of deterioration in drivability and the occupant are reduced. The amount of shock to be received is calculated, and it is determined whether the calculated deterioration amount and the shock amount fall within an allowable range. If it is determined that at least one of the deterioration amount and the shock amount exceeds the allowable range, the compressor 5 The control of the compressor 5 that changes the power consumption is prohibited.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a control device for a vehicle that drives a plurality of loads including a refrigerant compressor by a common drive source.
[0002]
[Prior art]
In a vehicle that has an internal combustion engine (hereinafter referred to as an engine) and an electric motor as driving sources for the vehicle and automatically stops and restarts the engine under predetermined conditions, the effect of improving the fuel efficiency and reducing the harmful exhaust gas by stopping the engine is reduced. Various devices have been proposed to maintain comfort by using an air conditioner while suppressing air pollution (Japanese Unexamined Patent Application Publication No. 2000-179374, “Toyota Motor Corporation Prius New Model Manual”, published October 1997). (See page 53, "THS-M System" announced by Toyota Motor Corporation on June 12, 2000).
[0003]
Further, even in a vehicle that does not automatically stop and restart the engine, there is known a vehicle in which the operation start / stop conditions of the compressor are set according to the engine speed, the acceleration / deceleration state of the vehicle, and the like, in order to save fuel. (See "Toyota Motor Co., Ltd. Mark II New Model Manual", October 4-2000, page 4-55).
[0004]
[Problems to be solved by the invention]
However, in the former conventional device, the automatic stop and automatic restart of the engine and the drive and stop of the electric motor are determined according to the demand condition of the indoor comfort such as the maintenance of the vehicle interior temperature. There is a problem that a shock accompanying the driving and stopping of the electric motor is generated, which causes discomfort to the occupant.
[0005]
Further, in the latter conventional device, there is a problem that a shock is generated with the operation / stop of the compressor, and the occupant is deteriorated in drivability and uncomfortable.
[0006]
The present invention has been made in view of the above points, and in a vehicle in which a plurality of loads including a refrigerant compressor are driven by a common drive source, the occupants should be given as little discomfort as possible due to deterioration in drivability and shock. The purpose is to do.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, a compressor (5) for compressing and discharging a refrigerant and a drive source (1, 2) for driving a plurality of loads including the compressor (5). A control device for a vehicle, comprising: an output or a moment of inertia of a drive source (1, 2); power consumption of a load excluding a compressor (5) among a plurality of loads; and consumption of a compressor (5). Based on the expected power change, the drivability deterioration amount and the shock amount received by the occupant are calculated, and it is determined whether the calculated deterioration amount and the shock amount fall within an allowable range, and the deterioration amount and the shock amount are determined. When it is determined that at least one of them exceeds the allowable range, the control of the compressor (5) that changes the power consumption of the compressor (5) is prohibited.
[0008]
According to this, when it is determined that at least one of the drivability deterioration amount and the shock amount exceeds the allowable range, control of the compressor such that the power consumption of the compressor is changed is prohibited. The deterioration of drivability due to the change of the vehicle and the discomfort caused by the shock can be prevented.
[0009]
According to the second aspect of the present invention, the compressor (5) that compresses and discharges the refrigerant and has a variable discharge capacity, and the drive source (1, 2) that drives a plurality of loads including the compressor (5). A control device for a vehicle, comprising: an output or a moment of inertia of a drive source (1, 2); power consumption of a load other than the compressor (5) among a plurality of loads; and a discharge of the compressor (5). Based on the expected change in power consumption due to the capacity change, the amount of deterioration in drivability and the amount of shock received by the occupant are calculated, and it is determined whether the calculated amount of deterioration and the amount of shock fall within an allowable range, When it is determined that at least one of the deterioration amount and the shock amount exceeds the allowable range, the discharge capacity of the compressor (5) changes more gradually than when it is determined that the deterioration amount and the shock amount fall within the allowable range. Feature To.
[0010]
According to this, when it is determined that at least one of the drivability deterioration amount and the shock amount exceeds the allowable range, the discharge capacity of the compressor is gradually changed, and the power consumption of the compressor is gradually changed. Deterioration of drivability and discomfort due to shock can be prevented.
[0011]
According to the third aspect of the present invention, a control device for a vehicle includes a compressor (5) for compressing and discharging a refrigerant, and a drive source (1, 2) for driving a plurality of loads including the compressor (5). The output or the moment of inertia of the driving sources (1, 2), the power consumption of the loads other than the compressor (5) out of the plurality of loads, and the expected power consumption change of the compressor (5). Based on the calculated drivability deterioration amount and the shock amount received by the occupant, it is determined whether the calculated deterioration amount and the shock amount fall within an allowable range, and at least one of the deterioration amount and the shock amount falls within the allowable range. When it is determined to exceed, the output of the driving source (1, 2) is adjusted.
[0012]
According to this, when it is determined that at least one of the drivability deterioration amount and the shock amount exceeds the allowable range, the output of the drive source is adjusted in accordance with the expected change in the power consumption of the compressor, whereby the driver is adjusted. It is possible to prevent the deterioration of the ability and the discomfort due to the shock.
[0013]
According to a fourth aspect of the present invention, a compressor (5) for compressing and discharging a refrigerant and a plurality of drive sources (1, 2) for driving a plurality of loads including the compressor (5) are provided. A control device for a vehicle that switches drive sources (1, 2) for driving a compressor (5) according to conditions, wherein the drive sources (1, 2) for driving a compressor (5) are changed from one drive source to the other. Output power or moment of inertia of the driving sources (1 and 2) when switching to the driving source of the second type, power consumption of a load other than the compressor (5) among a plurality of loads, and change in power consumption of the compressor (5). Based on the minutes, the drivability deterioration amount and the shock amount received by the occupant are calculated, and it is determined whether or not the calculated deterioration amount and the shock amount fall within an allowable range. At least one of the deterioration amount and the shock amount is determined. If it is determined that the value exceeds the allowable range, the compressor (5 And inhibits the switching of the drive source (1,2) for driving the.
[0014]
According to this, when it is determined that at least one of the drivability deterioration amount and the shock amount exceeds the allowable range, the switching of the driving source for driving the compressor is prohibited by prohibiting the switching of the driving source for driving the compressor. This can prevent the drivability from deteriorating and the discomfort due to the shock.
[0015]
In addition, the code | symbol in the parenthesis of each said means shows the correspondence with the concrete means described in embodiment mentioned later.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
1 to 3 show a first embodiment of the present invention. The overall configuration of a hybrid vehicle will be described with reference to FIG.
[0017]
The hybrid vehicle includes an internal combustion engine (hereinafter, referred to as an engine) 1 using gasoline as a fuel and a motor generator 2 as a vehicle traveling drive source. The motor generator 2 functions as a motor that generates motive power when supplied with power from a battery (not shown), and functions as a generator that generates power when driven by the engine 1 or the like.
[0018]
The hybrid vehicle also includes, as accessories driven by the engine 1 and the motor generator 2, a water pump 3 for circulating engine cooling water, a power steering pump 4 for generating hydraulic pressure, which is a component of power steering, and a refrigerant. And a compressor 5 for compressing and discharging the compressed air.
[0019]
The compressor 5 constitutes a refrigeration cycle of a vehicle air conditioner together with a condenser, a liquid receiver, an expansion valve, and an evaporator (not shown). The compressor 5 is a variable displacement compressor whose discharge capacity is adjusted by an output control valve 51.
[0020]
The engine 1, the motor generator 2, the water pump 3, the power steering pump 4, and the compressor 5 are connected by a belt 6. The engine 1 is connected to the belt 6 via an electromagnetic clutch 11, and the compressor 5 is connected to the belt 6 via an electromagnetic clutch 52.
[0021]
The power of the engine is transmitted to driving wheels 8 via a transmission 7. When the clutch 11 of the engine 1 is in a connected state capable of transmitting power, the power of the motor generator 2 can be transmitted to the drive wheels 8 via the belt 6, the clutch 11, and the like.
[0022]
The electronic control unit 9 includes a microcomputer and its peripheral circuits, and performs various calculations and processes based on a control program stored in advance. The electronic control unit 9 includes an engine 1, a motor generator 2, a compressor 5, and a transmission. 7 is controlled.
[0023]
More specifically, the electronic control unit 9 controls the eco-run control for automatically stopping and automatically restarting the engine 1 under a predetermined condition, the engine output control for adjusting the output of the engine 1, and the operation of the motor generator 2 as a motor. The function switching control as to whether it functions as a generator, the shift control of the transmission 7, and the air conditioning control of the vehicle air conditioner including the compressor 5 are performed.
[0024]
The compressor 5 can be driven by either the engine 1 or the motor generator 2, and is selectively driven by either the engine 1 or the motor generator 2 according to conditions such as a vehicle running state. Therefore, the engine 1 and the motor generator 2 correspond to the drive source of the present invention.
[0025]
The basic operation of the hybrid vehicle having the above configuration will be described.
[0026]
First, while the vehicle is stopped, the engine 1 is stopped, and the clutch 11 of the engine 1 is brought into a disconnected state in which power is not transmitted. On the other hand, the compressor 5 is driven by the motor generator 2 with the clutch 52 of the compressor 5 being connected, and the air conditioning in the vehicle compartment is performed by the vehicle air conditioner. At the time of starting, the clutch 11 of the engine 1 is connected, and the engine 1 is restarted while the vehicle and the compressor 5 are driven by the power of the motor generator 2.
[0027]
During normal traveling, the vehicle and the compressor 5 are driven by the engine 1. In addition, during normal running, if the battery charge becomes insufficient, the motor generator 2 is driven by the engine 1 to act as a generator, and charge the battery. At the time of deceleration, the motor generator 2 is driven from the driving wheel 8 side to charge the battery from the motor generator 2.
[0028]
Next, control for reducing drivability when the power consumption of the compressor 5 changes and for reducing shock to the occupant will be described.
[0029]
FIGS. 2 and 3 show a part of the control processing executed by the electronic control unit 9. In step S10, the compressor 5 among the driving sources of the engine 1 and the motor generator 2 is currently driven. Calculate the output or moment of inertia of the drive source that is located.
[0030]
Next, in step S20, the output or the moment of inertia of the drive source during the switching of the drive source for driving the compressor 5 from one drive source to the other drive source is calculated. For example, in the case where the compressor 5 driven by the engine 1 is switched to be driven by the motor generator 2, “in the middle of switching the compressor drive source” in step S <b> 20 refers to the engine 1 and the motor generator 2. Can be defined as follows according to the control pattern of
[0031]
That is, (1) when the operation of the motor generator 2 is started after the engine 1 is stopped, (2) when the engine 1 is stopped until the engine 1 is stopped after the stop of the engine 1 is determined. When the operation of the motor generator 2 is started from (3), during the period from the start of rotation of the motor generator 2 to the reaching of the target rotation speed, (3) when the operation of the motor generator 2 is started while the engine 1 is stopped. , From when the engine stop is determined or when the motor generator starts rotating, until the engine 1 stops and the motor generator 2 reaches the target rotation speed.
[0032]
Next, in step S30, the power consumption of the compressor 5 other than the compressor 5, that is, the power consumption of the water pump 3 and the power steering pump 4, and the vehicle driving power are calculated. In step S40, the power consumption of the compressor 5 is calculated. calculate.
[0033]
Next, in step S50, it is determined whether or not the power consumption of the compressor 5 is scheduled to change. For example, when it is necessary to change the discharge capacity of the compressor 5 due to a change in the air conditioning heat load, step S50 is YES and the process proceeds to step S60.
[0034]
In step S60, the difference between the current power consumption of the compressor 5 and the power consumption of the compressor 5 when the discharge capacity is changed, that is, the expected increase / decrease amount of the power consumption of the compressor 5 is calculated.
[0035]
Next, in step S70, based on the output or the moment of inertia calculated in step S10, the power consumption other than the compressor 5 calculated in step S30, and the expected power consumption increase / decrease amount of the compressor 5 calculated in step S60. Then, the amount of deterioration in drivability when the power consumption of the compressor 5 changes by the expected increase / decrease amount calculated in step S60 is calculated, and in step S80, the output or the moment of inertia calculated in step S20 and the moment of inertia are calculated in step S30. Drivability when the power consumption of the compressor 5 changes by the expected increase / decrease amount calculated in step S60 based on the power consumption other than the compressor 5 and the expected increase / decrease amount of power consumption of the compressor 5 calculated in step S60. Is calculated.
[0036]
Next, in step S90, based on the output or the moment of inertia calculated in step S10, the power consumption other than the compressor 5 calculated in step S30, and the estimated power consumption increase / decrease amount of the compressor 5 calculated in step S60. The amount of shock received by the occupant when the power consumption of the compressor 5 changes by the expected increase / decrease amount calculated in step S60 is calculated. In step S100, the output or moment of inertia calculated in step S20 and the moment of inertia are calculated in step S30. The occupant when the power consumption of the compressor 5 has changed by the expected increase / decrease amount calculated in step S60 based on the power consumption other than the compressor 5 and the expected increase / decrease amount of power consumption of the compressor 5 calculated in step S60. Calculate the amount of shock received.
[0037]
Next, in step S110, it is determined whether the drive source for driving the compressor 5 is scheduled to switch from the engine 1 to the motor generator 2 or vice versa. If S110 is YES, the process proceeds to step S120.
[0038]
In this step S120, it is determined whether both the drivability deterioration amount calculated in steps S80 and S100 and the shock amount received by the occupant fall within an allowable range, and it is determined that both of them fall within an allowable range. If S120 is YES, the process proceeds to step S130. In step S130, the drive source for driving the compressor 5 is switched. Further, the process proceeds to step S140 to change the power consumption of the compressor 5, that is, to change the discharge capacity of the compressor 5. . Incidentally, regarding the amount of shock, the allowable acceleration is, for example, 0.3 m / s ² or less.
[0039]
On the other hand, if it is determined that at least one of the drivability deterioration amount calculated in steps S80 and S100 and the shock amount received by the occupant exceeds the allowable range, step S120 is NO and the process proceeds to step S150. In this step S150, increase / decrease of power consumption of the compressor 5, that is, change of the displacement of the compressor 5 is prohibited.
[0040]
If step S110 is NO, that is, if there is no plan to switch the drive source for driving the compressor 5, the process proceeds to step S160.
[0041]
In this step S160, it is determined whether or not both the drivability deterioration amount calculated in steps S70 and S90 and the shock amount received by the occupant fall within an allowable range, and it is determined that both of them fall within an allowable range. If S160 is YES, the process proceeds to step S170, in which the power consumption of the compressor 5 is changed, that is, the discharge capacity of the compressor 5 is changed.
[0042]
On the other hand, when it is determined that at least one of the drivability deterioration amount calculated in steps S70 and S90 and the shock amount received by the occupant exceeds the allowable range, step S160 is NO and the process proceeds to step S180. In this step S180, increase / decrease of power consumption of the compressor 5, that is, change of the displacement of the compressor 5 is prohibited.
[0043]
According to the present embodiment, when it is determined that at least one of the drivability deterioration amount and the shock amount received by the occupant exceeds the allowable range, the increase or decrease of the power consumption of the compressor 5 is prohibited, and the drivability deterioration amount and the shock amount are reduced. When both are determined to fall within the allowable range, the increase or decrease of the power consumption of the compressor 5 is permitted, so that the drivability deterioration amount and the shock amount can be within the allowable range.
[0044]
In this embodiment, the variable displacement compressor 5 is used, but a fixed displacement compressor may be used. When a fixed displacement compressor is used, in step S150 and step S180, a change in the operation or stop state of the compressor 5 is prohibited, so that an increase or decrease in power consumption of the compressor 5 is prohibited.
[0045]
(2nd Embodiment)
In the first embodiment, when it is determined that at least one of the drivability deterioration amount and the occupant shock amount exceeds the allowable range, the increase or decrease in the power consumption of the compressor 5 is prohibited. In this example, the discharge capacity of the compressor 5 is gradually changed.
[0046]
Therefore, in the present embodiment, the control contents shown in FIG. 3 in the first embodiment are changed as shown in FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. The overall configuration of the hybrid vehicle is the same as that of the first embodiment.
[0047]
In FIG. 4, when it is determined that both the drivability deterioration amount and the shock amount received by the occupant fall within the allowable range, that is, if step S120 or step S160 is YES, in step S140 or step S170, the consumption of the compressor 5 is determined. The power is changed, and more specifically, the discharge capacity of the compressor 5 is quickly changed to the target discharge capacity.
[0048]
On the other hand, if it is determined that at least one of the drivability deterioration amount and the shock amount received by the occupant exceeds the allowable range, and step S120 or step S160 is NO, the process proceeds to step S150A or step S180A.
[0049]
In these steps S150A and S180A, a sudden change in the power consumption of the compressor 5 is prohibited. Specifically, a sudden change in the power consumption of the compressor 5 is prevented by gradually changing the discharge capacity of the compressor 5 compared to when the discharge capacity of the compressor 5 is changed in steps S140 and S170.
[0050]
According to the present embodiment, when it is determined that at least one of the drivability deterioration amount and the shock amount received by the occupant exceeds the allowable range, compared to when it is determined that the drivability deterioration amount and the shock amount fall within the allowable range. Since the power consumption of the compressor 5 is gradually changed by gradually changing the discharge capacity of the compressor 5, it is possible to keep the drivability deterioration amount and the shock amount within an allowable range.
[0051]
(Third embodiment)
In the first embodiment, when it is determined that at least one of the drivability deterioration amount and the occupant shock amount exceeds the allowable range, the increase or decrease in the power consumption of the compressor 5 is prohibited. In this example, the outputs of the engine 1 and the motor generator 2 are adjusted.
[0052]
Therefore, in the present embodiment, the control contents shown in FIG. 3 in the first embodiment are changed as shown in FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. The overall configuration of the hybrid vehicle is the same as that of the first embodiment.
[0053]
In FIG. 5, when it is determined that at least one of the deterioration amount of drivability and the shock amount received by the occupant exceeds the allowable range, and step S120 or step S160 is NO, the process proceeds to step S150B or step S180B.
[0054]
In step S150B, the drive source output during switching of the compressor drive source, that is, the output of at least one of the engine 1 and the motor generator 2 is adjusted. Specifically, if the power consumption of the compressor 5 is going to increase, the drive source output is increased, and if the power consumption of the compressor 5 is going to decrease, the drive source output is decreased.
[0055]
In step S180B, the output of one of the drive source that is currently driving compressor 5, that is, one of engine 1 and motor generator 2 is adjusted. Specifically, if the power consumption of the compressor 5 is going to increase, the drive source output is increased, and if the power consumption of the compressor 5 is going to decrease, the drive source output is decreased.
[0056]
According to the present embodiment, when it is determined that at least one of the drivability deterioration amount and the shock amount received by the occupant exceeds the allowable range, the output of the compressor drive source is adjusted according to the increase or decrease of the power consumption of the compressor 5. Therefore, the drivability deterioration amount and the shock amount can be kept within the allowable range.
[0057]
(Fourth embodiment)
In the first embodiment, when it is determined that at least one of the drivability deterioration amount during the switching of the compressor drive source and the shock amount to the occupant exceeds the allowable range, the increase or decrease of the power consumption of the compressor 5 is prohibited. On the other hand, in the present embodiment, switching of the compressor drive source is prohibited.
[0058]
Therefore, in the present embodiment, the control contents shown in FIG. 3 in the first embodiment are changed as shown in FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. The overall configuration of the hybrid vehicle is the same as that of the first embodiment.
[0059]
In FIG. 6, when it is determined that at least one of the drivability deterioration amount during the switching of the compressor drive source and the shock amount received by the occupant exceeds the allowable range, and step S120 is NO, the process proceeds to step S150C, and the compressor drive is performed. Prohibit source switching. According to this, it is possible to prevent the drivability from deteriorating due to the switching of the drive source for driving the compressor 5 and the discomfort due to the shock.
[0060]
(Other embodiments)
In the above embodiment, the engine 1 and the motor generator 2 are used as the drive sources of the compressor 5, but other drive sources may be used.
[0061]
In addition, during the fuel cut when the vehicle is decelerated, the work amount of the compressor 5 is increased to store cold energy, and the work amount of the compressor 5 after the fuel cut is completed is reduced, so as to achieve low shock and low fuel consumption. Is also good. Similarly, when the air temperature at the portion of the evaporator constituting the refrigeration cycle, that is, the actual evaporator temperature is lower than the target evaporator temperature, the work amount of the compressor 5 after the fuel cut is reduced, Low shock and low fuel consumption may be achieved.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a first embodiment of the present invention.
FIG. 2 is a flowchart illustrating a main part of control according to the first embodiment.
FIG. 3 is a flowchart illustrating a main part of control according to the first embodiment.
FIG. 4 is a flowchart illustrating a main part of control according to a second embodiment.
FIG. 5 is a flowchart illustrating a main part of control according to a third embodiment.
FIG. 6 is a flowchart illustrating a main part of control according to a fourth embodiment.
[Explanation of symbols]
1 ... Engine (drive source), 2 ... Motor generator (drive source), 5 ... Compressor.

Claims (4)

A control device for a vehicle, comprising: a compressor (5) for compressing and discharging a refrigerant; and a driving source (1, 2) for driving a plurality of loads including the compressor (5),
The output or the moment of inertia of the drive sources (1, 2), the power consumption of the loads other than the compressor (5) out of the plurality of loads, and the expected power consumption change of the compressor (5). Based on the calculated amount of deterioration of drivability and the amount of shock received by the occupant,
Determine whether the calculated deterioration amount and the shock amount fall within an allowable range,
When it is determined that at least one of the deterioration amount and the shock amount exceeds the allowable range, control of the compressor (5) such that power consumption of the compressor (5) changes is prohibited. Vehicle control device. A control device for a vehicle including a compressor (5) that compresses and discharges a refrigerant and has a variable discharge capacity, and a drive source (1, 2) that drives a plurality of loads including the compressor (5). So,
The output or the moment of inertia of the driving sources (1, 2), the power consumption of the loads other than the compressor (5) out of the plurality of loads, and the power consumption due to the change in the discharge capacity of the compressor (5). Based on the expected change, the amount of deterioration in drivability and the amount of shock received by the occupant are calculated,
Determine whether the calculated deterioration amount and the shock amount fall within an allowable range,
When it is determined that at least one of the deterioration amount and the shock amount exceeds the allowable range, the compressor (5) is more strongly than when it is determined that the deterioration amount and the shock amount fall within the allowable range. A control device for a vehicle, wherein the discharge capacity of the vehicle is gradually changed. A control device for a vehicle, comprising: a compressor (5) for compressing and discharging a refrigerant; and a driving source (1, 2) for driving a plurality of loads including the compressor (5),
The output or the moment of inertia of the drive sources (1, 2), the power consumption of the loads other than the compressor (5) out of the plurality of loads, and the expected power consumption change of the compressor (5). Based on the calculated amount of deterioration of drivability and the amount of shock received by the occupant,
Determine whether the calculated deterioration amount and the shock amount fall within an allowable range,
When at least one of the deterioration amount and the shock amount is determined to exceed the allowable range, the output of the drive source (1, 2) is adjusted. A compressor (5) for compressing and discharging the refrigerant; and a plurality of drive sources (1, 2) for driving a plurality of loads including the compressor (5), for driving the compressor (5). A control device for a vehicle that switches the drive sources (1, 2) according to conditions,
An output or moment of inertia of the drive source (1, 2) when the drive source (1, 2) for driving the compressor (5) switches from one drive source to another drive source, and the plurality of loads Calculating, based on the power consumption of the load excluding the compressor (5) and the expected power consumption change of the compressor (5), the drivability deterioration amount and the shock amount received by the occupant;
Determine whether the calculated deterioration amount and the shock amount fall within an allowable range,
When at least one of the deterioration amount and the shock amount is determined to exceed the allowable range, switching of the drive sources (1, 2) for driving the compressor (5) is prohibited. Control device.

Images